Author: "PESCE-ROLLINS, M." / Publisher: stockholms universitet, fysikum - Searchworks@Jio Institute Digital Library Search Results

Your search keyword '"PESCE-ROLLINS, M."' showing total 73 results

Start Over Author "PESCE-ROLLINS, M." Publisher stockholms universitet, fysikum

73 results on '"PESCE-ROLLINS, M."'

1. Fermi Large Area Telescope Performance after 10 Years of Operation

Author: Ajello, M., Atwood, W. B., Axelsson, Magnus, Bagagli, R., Bagni, M., Baldini, L., Bastieri, D., Bellardi, F., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bregeon, J., Brez, A., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Ceccanti, M., Chen, S., Cheung, C. C., Ciprini, S., Cognard, I., Cohen-Tanugi, J., Cutini, S., D'Ammando, F., de la Torre Luque, P., de Palma, F., Digel, S. W., Dirirsa, F., Di Lalla, N., Di Venere, L., Dominguez, A., Fabiani, D., Ferrara, E. C., Fiori, A., Foglia, G., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Giroletti, M., Glanzman, T., Green, D., Griffin, S., Grondin, M.-H., Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hays, E., Horan, D., Jóhannesson, Guðlaugur, Johnson, T. J., Kamae, T., Kerr, M., Kuss, M., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Liodakis, I., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Manfreda, A., Marti-Devesa, G., Mazziotta, M. N., Menon, N., Mereu, I., Meyer, M., Michelson, P. F., Minuti, M., Mitthumsiri, W., Mizuno, T., Mongelli, M., Monzani, M. E., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Orienti, M., Orlando, E., Paccagnella, A., Paliya, V. S., Paneque, D., Pei, Z., Perkins, J. S., Pesce-Rollins, M., Pinchera, M., Piron, F., Poon, H., Porter, T. A., Primavera, R., Principe, G., Racusin, J. L., Raino, S., Rando, R., Rani, B., Rapposelli, E., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Russell, J. J., Saggini, N., Saz Parkinson, P. M., Scolieri, N., Serini, D., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Valverde, J., Vigiani, L., Zaharijas, G., Ajello, M., Atwood, W. B., Axelsson, Magnus, Bagagli, R., Bagni, M., Baldini, L., Bastieri, D., Bellardi, F., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bregeon, J., Brez, A., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Ceccanti, M., Chen, S., Cheung, C. C., Ciprini, S., Cognard, I., Cohen-Tanugi, J., Cutini, S., D'Ammando, F., de la Torre Luque, P., de Palma, F., Digel, S. W., Dirirsa, F., Di Lalla, N., Di Venere, L., Dominguez, A., Fabiani, D., Ferrara, E. C., Fiori, A., Foglia, G., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Giroletti, M., Glanzman, T., Green, D., Griffin, S., Grondin, M.-H., Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Hays, E., Horan, D., Jóhannesson, Guðlaugur, Johnson, T. J., Kamae, T., Kerr, M., Kuss, M., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Liodakis, I., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Manfreda, A., Marti-Devesa, G., Mazziotta, M. N., Menon, N., Mereu, I., Meyer, M., Michelson, P. F., Minuti, M., Mitthumsiri, W., Mizuno, T., Mongelli, M., Monzani, M. E., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Orienti, M., Orlando, E., Paccagnella, A., Paliya, V. S., Paneque, D., Pei, Z., Perkins, J. S., Pesce-Rollins, M., Pinchera, M., Piron, F., Poon, H., Porter, T. A., Primavera, R., Principe, G., Racusin, J. L., Raino, S., Rando, R., Rani, B., Rapposelli, E., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Russell, J. J., Saggini, N., Saz Parkinson, P. M., Scolieri, N., Serini, D., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Valverde, J., Vigiani, L., and Zaharijas, G.
Abstract: The Large Area Telescope (LAT), the primary instrument for the Fermi Gamma-ray Space Telescope (Fermi) mission, is an imaging, wide field-of-view, high-energy gamma-ray telescope, covering the energy range from 30 MeV to more than 300 GeV. We describe the performance of the instrument at the 10 yr milestone. LAT performance remains well within the specifications defined during the planning phase, validating the design choices and supporting the compelling case to extend the duration of the Fermi mission. The details provided here will be useful when designing the next generation of high-energy gamma-ray observatories.
Published: 2021
Full Text: View/download PDF

2. The Fourth Catalog of Active Galactic Nuclei Detected by the Fermi Large Area Telescope

Author: Ajello, M., Angioni, R., Axelsson, Magnus, Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Bruel, P., Buson, S., Cafardo, F., Cameron, R. A., Cavazzuti, E., Chen, S., Cheung, C. C., Ciprini, S., Costantin, D., Cutini, S., D'Ammando, F., de la Torre Luque, P., de Menezes, R., de Palma, F., Desai, A., Di Lalla, N., Di Venere, L., Dominguez, A., Fana Dirirsa, F., Ferrara, E. C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Garrappa, S., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guiriec, S., Harita, S., Hays, E., Horan, D., Itoh, R., Jóhannesson, Guðlaugur, Kovac'evic', M., Krauss, F., Kreter, M., Kuss, M., Larsson, S., Leto, C., Li, J., Liodakis, I., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Marti-Devesa, G., Massaro, F., Mazziotta, M. N., Mereu, I., Meyer, M., Migliori, G., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I., Negro, M., Nemmen, R., Nuss, E., Ojha, L. S., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paliya, V. S., Pei, Z., Pena-Herazo, H., Persic, M., Pesce-Rollins, M., Petrov, L., Piron, F., Poon, H., Principe, G., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Schinzel, F. K., Serini, D., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tachibana, Y., Thompson, D. J., Torres, D. F., Torresi, E., Troja, E., Valverde, J., van Zyl, P., Yassine, M., Ajello, M., Angioni, R., Axelsson, Magnus, Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Bruel, P., Buson, S., Cafardo, F., Cameron, R. A., Cavazzuti, E., Chen, S., Cheung, C. C., Ciprini, S., Costantin, D., Cutini, S., D'Ammando, F., de la Torre Luque, P., de Menezes, R., de Palma, F., Desai, A., Di Lalla, N., Di Venere, L., Dominguez, A., Fana Dirirsa, F., Ferrara, E. C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Garrappa, S., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guiriec, S., Harita, S., Hays, E., Horan, D., Itoh, R., Jóhannesson, Guðlaugur, Kovac'evic', M., Krauss, F., Kreter, M., Kuss, M., Larsson, S., Leto, C., Li, J., Liodakis, I., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Marti-Devesa, G., Massaro, F., Mazziotta, M. N., Mereu, I., Meyer, M., Migliori, G., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I., Negro, M., Nemmen, R., Nuss, E., Ojha, L. S., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paliya, V. S., Pei, Z., Pena-Herazo, H., Persic, M., Pesce-Rollins, M., Petrov, L., Piron, F., Poon, H., Principe, G., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Schinzel, F. K., Serini, D., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tachibana, Y., Thompson, D. J., Torres, D. F., Torresi, E., Troja, E., Valverde, J., van Zyl, P., and Yassine, M.
Published: 2020
Full Text: View/download PDF

3. Fermi and Swift Observations of GRB 190114C : Tracing the Evolution of High-energy Emission from Prompt to Afterglow

Author: Ajello, M., Arimoto, M., Axelsson, Magnus, Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Berretta, A., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Burns, E., Buson, S., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Chen, S., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Costantin, D., Cutini, S., D'Ammando, F., DeKlotz, M., Luque, P. de la Torre, de Palma, F., Desai, A., Di Lalla, N., Di Venere, L., Dirirsa, F. Fana, Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Gill, R., Giordano, F., Giroletti, M., Granot, J., Green, D., Grenier, I. A., Grondin, M. -H., Guiriec, S., Hays, E., Horan, D., Jóhannesson, Guðlaugur, Kocevski, D., Kovac'evic', M., Kuss, M., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Liodakis, I., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Marti-Devesa, G., Mazziotta, M. N., McEnery, J. E., Mereu, I., Meyer, M., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Pei, Z., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Poon, H., Porter, T. A., Principe, G., Racusin, J. L., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ryde, F., Parkinson, P. M. Saz, Serini, D., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Tajima, H., Takagi, K., Takahashi, M. N., Tak, D., Thayer, J. B., Thompson, D. J., Torres, D. F., Troja, E., Valverde, J., Van Klaveren, B., Wood, K., Yassine, M., Zaharijas, G., Mailyan, B., Bhat, P. N., Briggs, M. S., Cleveland, W., Giles, M., Goldstein, A., Hui, M., Malacaria, Christian, Preece, R., Roberts, O. J., Veres, P., Wilson-Hodge, C., von Kienlin, A., Cenko, S. B., O'Brien, P., Beardmore, A. P., Lien, A., Osborne, J. P., Tohuvavohu, A., D'Elia, V., D'Ai, A., Perri, M., Gropp, J., Klingler, N., Capalbi, M., Tagliaferri, G., Stamatikos, M., De Pasquale, M., Ajello, M., Arimoto, M., Axelsson, Magnus, Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Berretta, A., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Burns, E., Buson, S., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Chen, S., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Costantin, D., Cutini, S., D'Ammando, F., DeKlotz, M., Luque, P. de la Torre, de Palma, F., Desai, A., Di Lalla, N., Di Venere, L., Dirirsa, F. Fana, Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Gill, R., Giordano, F., Giroletti, M., Granot, J., Green, D., Grenier, I. A., Grondin, M. -H., Guiriec, S., Hays, E., Horan, D., Jóhannesson, Guðlaugur, Kocevski, D., Kovac'evic', M., Kuss, M., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Liodakis, I., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Marti-Devesa, G., Mazziotta, M. N., McEnery, J. E., Mereu, I., Meyer, M., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Pei, Z., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Poon, H., Porter, T. A., Principe, G., Racusin, J. L., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ryde, F., Parkinson, P. M. Saz, Serini, D., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Tajima, H., Takagi, K., Takahashi, M. N., Tak, D., Thayer, J. B., Thompson, D. J., Torres, D. F., Troja, E., Valverde, J., Van Klaveren, B., Wood, K., Yassine, M., Zaharijas, G., Mailyan, B., Bhat, P. N., Briggs, M. S., Cleveland, W., Giles, M., Goldstein, A., Hui, M., Malacaria, Christian, Preece, R., Roberts, O. J., Veres, P., Wilson-Hodge, C., von Kienlin, A., Cenko, S. B., O'Brien, P., Beardmore, A. P., Lien, A., Osborne, J. P., Tohuvavohu, A., D'Elia, V., D'Ai, A., Perri, M., Gropp, J., Klingler, N., Capalbi, M., Tagliaferri, G., Stamatikos, M., and De Pasquale, M.
Abstract: We report on the observations of gamma-ray burst (GRB) 190114C by the Fermi Gamma -ray Space Telescope and the Neil Gehrels Swift Observatory. The prompt gamma-ray emission was detected by the Fermi GRB Monitor (GBM), the Fermi Large Area Telescope (LAT), and the Swift Burst Alert Telescope (BAT) and the long-lived afterglow emission was subsequently observed by the GBM, LAT, Swift X-ray Telescope (XRT), and Swift UV Optical Telescope. The early -time observations reveal multiple emission components that evolve independently, with a delayed power-law component that exhibits significant spectral attenuation above 40 MeV in the first few seconds of the burst. This power-law component transitions to a harder spectrum that is consistent with the afterglow emission observed by the XRT at later times. This afterglow component is clearly identifiable in the GBM and BAT light curves as a slowly fading emission component on which the rest of the prompt emission is superimposed. As a result, we are able to observe the transition from internal-shock- to external-shock-dominated emission. We find that the temporal and spectral evolution of the broadband afterglow emission can be well modeled as synchrotron emission from a forward shock propagating into a wind -like circumstellar environment. We estimate the initial bulk Lorentz factor using the observed high-energy spectral cutoff. Considering the onset of the afterglow component, we constrain the deceleration radius at which this forward shock begins to radiate in order to estimate the maximum synchrotron energy as a function of time. We find that even in the LAT energy range, there exist high-energy photons that are in tension with the theoretical maximum energy that can be achieved through synchrotron emission from a shock. These violations of the maximum synchrotron energy are further compounded by the detection of very high-energy (VHE) emission above 300 GeV by MAGIC concurrent with our observations. We conclude that the
Published: 2020
Full Text: View/download PDF

4. A Decade of Gamma-Ray Bursts Observed by Fermi-LAT : The Second GRB Catalog

Author: Ajello, M., Arimoto, M., Axelsson, Magnus, Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bhat, P. N., Bissaldi, E., Blandford, R. D., Bonino, R., Bonnell, J., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Chen, S., Cheung, C. C., Chiaro, G., Ciprini, S., Costantin, D., Crnogorcevic, M., Cutini, S., Dainotti, M., D'Ammando, F., Luque, P. de la Torre, de Palma, F., Desai, A., Desiante, R., Di Lalla, N., Di Venere, L., Dirirsa, F. Fana, Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Grove, J. E., Guiriec, S., Hays, E., Hewitt, J. W., Horan, D., Jóhannesson, Guðlaugur, Kocevski, D., Kuss, M., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Manfreda, A., Marti-Devesa, G., Mazziotta, M. N., Mereu, I, Meyer, M., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I., Negro, M., Nuss, E., Ohno, M., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Persic, M., Pesce-Rollins, M., Petrosian, V, Piron, F., Poolakkil, S., Poon, H., Porter, T. A., Principe, G., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ryde, F., Serini, D., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, M., Tak, D., Thayer, J. B., Torres, D. F., Troja, E., Valverde, J., Veres, P., Vianello, G., von Kienlin, A., Wood, K., Yassine, M., Zhu, S., Zimmer, S., Ajello, M., Arimoto, M., Axelsson, Magnus, Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bhat, P. N., Bissaldi, E., Blandford, R. D., Bonino, R., Bonnell, J., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Chen, S., Cheung, C. C., Chiaro, G., Ciprini, S., Costantin, D., Crnogorcevic, M., Cutini, S., Dainotti, M., D'Ammando, F., Luque, P. de la Torre, de Palma, F., Desai, A., Desiante, R., Di Lalla, N., Di Venere, L., Dirirsa, F. Fana, Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Grove, J. E., Guiriec, S., Hays, E., Hewitt, J. W., Horan, D., Jóhannesson, Guðlaugur, Kocevski, D., Kuss, M., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Manfreda, A., Marti-Devesa, G., Mazziotta, M. N., Mereu, I, Meyer, M., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I., Negro, M., Nuss, E., Ohno, M., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Persic, M., Pesce-Rollins, M., Petrosian, V, Piron, F., Poolakkil, S., Poon, H., Porter, T. A., Principe, G., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ryde, F., Serini, D., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, M., Tak, D., Thayer, J. B., Torres, D. F., Troja, E., Valverde, J., Veres, P., Vianello, G., von Kienlin, A., Wood, K., Yassine, M., Zhu, S., and Zimmer, S.
Abstract: The Large Area Telescope (LAT) aboard the Fermi spacecraft routinely observes high-energy emission from gamma-ray bursts (GRBs). Here we present the second catalog of LAT-detected GRBs, covering the first 10 yr of operations, from 2008 to 2018 August 4. A total of 186 GRBs are found; of these, 91 show emission in the range 30-100 MeV (17 of which are seen only in this band) and 169 are detected above 100 MeV. Most of these sources were discovered by other instruments (Fermi/GBM, Swift/BAT, AGILE, INTEGRAL) or reported by the Interplanetary Network (IPN); the LAT has independently triggered on four GRBs. This catalog presents the results for all 186 GRBs. We study onset, duration, and temporal properties of each GRB, as well as spectral characteristics in the 100 MeV-100 GeV energy range. Particular attention is given to the photons with the highest energy. Compared with the first LAT GRB catalog, our rate of detection is significantly improved. The results generally confirm the main findings of the first catalog: the LAT primarily detects the brightest GBM bursts, and the high-energy emission shows delayed onset as well as longer duration. However, in this work we find delays exceeding 1 ks and several GRBs with durations over 10 ks. Furthermore, the larger number of LAT detections shows that these GRBs not only cover the high-fluence range of GBM-detected GRBs but also sample lower fluences. In addition, the greater number of detected GRBs with redshift estimates allows us to study their properties in both the observer and rest frames. Comparison of the observational results with theoretical predictions reveals that no model is currently able to explain all results, highlighting the role of LAT observations in driving theoretical models.
Published: 2019
Full Text: View/download PDF

5. A gamma-ray determination of the Universe's star formation history

Author: Abdollahi, S., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Buson, S., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Charles, E., Chen, S., Cheung, C. C., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Costantin, D., Cutini, S., D'Ammando, F., de Palma, F., Desai, A., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Favuzzi, C., Fegan, S. J., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Romero, G. Gallardo, Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hartmann, D. H., Hays, E., Helgason, K., Horan, D., Johannesson, G., Kocevski, D., Kuss, M., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Magill, J. D., Maldera, S., Manfreda, A., Marcotulli, L., Mazziotta, M. N., McEnery, J. E., Meyer, M., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Palatiello, M., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Porter, T. A., Primack, J. R., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, M., Thayer, J. B., Tibaldo, L., Torres, D. F., Torresi, E., Tosti, G., Tramacere, A., Troja, E., Valverde, J., Vianello, G., Vogel, M., Wood, K., Zaharijas, G., Abdollahi, S., Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Buson, S., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Charles, E., Chen, S., Cheung, C. C., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Costantin, D., Cutini, S., D'Ammando, F., de Palma, F., Desai, A., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Favuzzi, C., Fegan, S. J., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Romero, G. Gallardo, Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hartmann, D. H., Hays, E., Helgason, K., Horan, D., Johannesson, G., Kocevski, D., Kuss, M., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Magill, J. D., Maldera, S., Manfreda, A., Marcotulli, L., Mazziotta, M. N., McEnery, J. E., Meyer, M., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Palatiello, M., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Porter, T. A., Primack, J. R., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, M., Thayer, J. B., Tibaldo, L., Torres, D. F., Torresi, E., Tosti, G., Tramacere, A., Troja, E., Valverde, J., Vianello, G., Vogel, M., Wood, K., and Zaharijas, G.
Abstract: The light emitted by all galaxies over the history of the Universe produces the extragalactic background light (EBL) at ultraviolet, optical, and infrared wavelengths. The EBL is a source of opacity for gamma rays via photon-photon interactions, leaving an imprint in the spectra of distant gamma-ray sources. We measured this attenuation using 739 active galaxies and one gamma-ray burst detected by the Fermi Large Area Telescope. This allowed us to reconstruct the evolution of the EBL and determine the star formation history of the Universe over 90% of cosmic time. Our star formation history is consistent with independent measurements from galaxy surveys, peaking at redshift z similar to 2. Upper limits of the EBL at the epoch of reionization suggest a turnover in the abundance of faint galaxies at z similar to 6.
Published: 2018
Full Text: View/download PDF

6. Search for Gamma-Ray Emission from Local Primordial Black Holes with the Fermi Large Area Telescope

Author: Ackermann, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Charles, E., Chekhtman, A., Cheung, C. C., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Costantin, D., D'Ammando, F., de Palma, F., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Horan, D., Johannesson, G., Johnson, C., Kensei, S., Kocevski, D., Kuss, M., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Malyshev, D., Manfreda, A., Mazziotta, M. N., McEnery, J. E., Meyer, M., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Palatiello, M., Paliya, V. S., Paneque, D., Persic, M., Pesce-Rollins, M., Piron, F., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Sanchez-Conde, M., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. G., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Valverde, J., Vianello, G., Wood, K., Wood, M., Zaharijas, G., Ackermann, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Berenji, B., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caraveo, P. A., Cavazzuti, E., Charles, E., Chekhtman, A., Cheung, C. C., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Costantin, D., D'Ammando, F., de Palma, F., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Horan, D., Johannesson, G., Johnson, C., Kensei, S., Kocevski, D., Kuss, M., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Malyshev, D., Manfreda, A., Mazziotta, M. N., McEnery, J. E., Meyer, M., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Palatiello, M., Paliya, V. S., Paneque, D., Persic, M., Pesce-Rollins, M., Piron, F., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Sanchez-Conde, M., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. G., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Valverde, J., Vianello, G., Wood, K., Wood, M., and Zaharijas, G.
Abstract: Black holes with masses below approximately 10(15) g are expected to emit gamma-rays with energies above a few tens of MeV, which can be detected by the Fermi Large Area Telescope (LAT). Although black holes with these masses cannot be formed as a result of stellar evolution, they may have formed in the early universe and are therefore called primordial black holes (PBHs). Previous searches for PBHs have focused on either short-timescale bursts or the contribution of PBHs to the isotropic gamma-ray emission. We show that, in cases of individual PBHs, the Fermi-LAT is most sensitive to PBHs with temperatures above approximately 16 GeV and masses 6 x 10(11) g, which it can detect out to a distance of about 0.03 pc. These PBHs have a remaining lifetime of months to years at the start of the Fermi mission. They would appear as potentially moving point sources with gamma-ray emission that become spectrally harder and brighter with time until the PBH completely evaporates. In this paper, we develop a new algorithm to detect the proper motion of gamma-ray point sources, and apply it to 318 unassociated point sources at a high galactic latitude in the third Fermi-LAT source catalog. None of the unassociated point sources with spectra consistent with PBH evaporation show significant proper motion. Using the nondetection of PBH candidates, we derive a 99% confidence limit on the PBH evaporation rate in the vicinity of Earth, <(rho)over dot>(PBH) < 7.2 x 10(3) pc(-3) yr(-1). This limit is similar to the limits obtained with ground-based gamma-ray observatories.
Published: 2018
Full Text: View/download PDF

7. The Fermi Galactic Center GeV Excess and Implications for Dark Matter

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Burnett, T. H., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiappo, Andrea, Chiaro, G., Ciprini, S., Conrad, Jan, Costanza, F., Cuoco, A., Cutini, S., D'Ammando, F., de Palmai, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, J., Ferrara, E. C., Fockes, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gaspanini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Gomez-Vargas, G. A., Green, D., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Harding, A. K., Hays, E., Hewitt, J. W., Horan, D., Jogler, T., Johnson, A. S., Kamae, T., Kocevski, D., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Malyshev, D., Manfreda, A., Martin, P., Mazziottam, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Negro, M., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sanchez-Conde, Miguel, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandrel, G., Spinelli, P., Suson, D. J., Tajima, H., Tanaka, K., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Uchiyama, Y., Vianello, G., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, S., Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Burnett, T. H., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiappo, Andrea, Chiaro, G., Ciprini, S., Conrad, Jan, Costanza, F., Cuoco, A., Cutini, S., D'Ammando, F., de Palmai, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, J., Ferrara, E. C., Fockes, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gaspanini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Gomez-Vargas, G. A., Green, D., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Gustafsson, M., Harding, A. K., Hays, E., Hewitt, J. W., Horan, D., Jogler, T., Johnson, A. S., Kamae, T., Kocevski, D., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Malyshev, D., Manfreda, A., Martin, P., Mazziottam, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Negro, M., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sanchez-Conde, Miguel, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandrel, G., Spinelli, P., Suson, D. J., Tajima, H., Tanaka, K., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Uchiyama, Y., Vianello, G., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, S.
Abstract: The region around the Galactic Center (GC) is now well established to be brighter at energies of a few GeV than what is expected from conventional models of diffuse gamma-ray emission and catalogs of known gamma-ray sources. We study the GeV excess using 6.5 yr of data from the Fermi Large Area Telescope. We characterize the uncertainty of the GC excess spectrum and morphology due to uncertainties in cosmic-ray source distributions and propagation, uncertainties in the distribution of interstellar gas in the Milky Way, and uncertainties due to a potential contribution from the Fermi bubbles. We also evaluate uncertainties in the excess properties due to resolved point sources of gamma rays. The GC is of particular interest, as it would be expected to have the brightest signal from annihilation of weakly interacting massive dark matter (DM) particles. However, control regions along the Galactic plane, where a DM signal is not expected, show excesses of similar amplitude relative to the local background. Based on the magnitude of the systematic uncertainties, we conservatively report upper limits for the annihilation cross-section as a function of particle mass and annihilation channel.
Published: 2017
Full Text: View/download PDF

8. Gamma-Ray Blazars within the First 2 Billion Years

Author: Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Conrad, Jan, Costantin, D., Costanza, F., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Focke, W. B., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hartmann, D. H., Hays, E., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kuss, M., La Mura, G., Larsson, Stefan, Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Manfreda, A., Marcotulli, L., Mazziotta, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romani, R. W., Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Stalin, C. S., Stawarz, L., Suson, D. J., Takahashi, M., Tanaka, K., Thayer, J. B., Thompson, D. J., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Conrad, Jan, Costantin, D., Costanza, F., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Focke, W. B., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hartmann, D. H., Hays, E., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kuss, M., La Mura, G., Larsson, Stefan, Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Manfreda, A., Marcotulli, L., Mazziotta, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Ojha, R., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Rani, B., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romani, R. W., Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Stalin, C. S., Stawarz, L., Suson, D. J., Takahashi, M., Tanaka, K., Thayer, J. B., Thompson, D. J., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Vianello, G., and Wood, K. S.
Abstract: The detection of high-redshift (z > 3) blazars enables the study of the evolution of the most luminous relativistic jets over cosmic time. More importantly, high-redshift blazars tend to host massive black holes and can be used to constrain the space density of heavy black holes in the early universe. Here, we report the first detection with the Fermi-Large Area Telescope of five gamma-ray-emitting blazars beyond z. =. 3.1, more distant than any blazars previously detected in.-rays gamma Among these five objects, NVSS J151002+570243 is now the most distant known gamma-ray-emitting blazar at z =. 4.31. These objects have steeply falling gamma-ray spectral energy distributions (SEDs), and. those that have been observed in X-rays have a very hard X-ray spectrum, both typical of powerful blazars. Their Compton dominance ( ratio of the inverse Compton to synchrotron peak luminosities) is also very large (>20). All of these properties place these objects among the most extreme members of the blazar population. Their optical spectra and the modeling of their optical-UV SEDs confirm that these objects harbor massive black holes (MBH similar to 10(8-10) M circle dot 8 10). We find that, at z approximate to 4, the space density of >10(9)M circle dot black holes hosted in radio-loud and radio-quiet active galactic nuclei are similar, implying that radio-loudness may play a key role in rapid black hole growth in the early universe.
Published: 2017
Full Text: View/download PDF

9. Observations of M31 and M33 with the Fermi Large Area Telescope : A Galactic Center Excess in Andromeda?

Author: Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiaro, G., Ciprini, S., Costanza, F., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Favuzzi, C., Funk, S., Fusco, P., Gargano, F., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hayashi, K., Hou, X., Johannesson, G., Kamae, T., Knodlseder, J., Kong, A. K. H., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Martin, P., Mazziotta, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Razzano, M., Reimer, O., Sanchez-Conde, Miguel, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Tanaka, K., Tibaldo, L., Torres, D. F., Troja, E., Uchiyama, Y., Wang, J. C., Wood, K. S., Wood, M., Zaharijas, G., Zhou, M., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiaro, G., Ciprini, S., Costanza, F., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Favuzzi, C., Funk, S., Fusco, P., Gargano, F., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Guillemot, L., Guiriec, S., Hayashi, K., Hou, X., Johannesson, G., Kamae, T., Knodlseder, J., Kong, A. K. H., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Martin, P., Mazziotta, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Razzano, M., Reimer, O., Sanchez-Conde, Miguel, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Tanaka, K., Tibaldo, L., Torres, D. F., Troja, E., Uchiyama, Y., Wang, J. C., Wood, K. S., Wood, M., Zaharijas, G., and Zhou, M.
Abstract: The Fermi Large Area Telescope (LAT) has opened the way for comparative studies of cosmic rays (CRs) and high-energy objects in the Milky Way (MW) and in other, external, star-forming galaxies. Using 2 yr of observations with the Fermi LAT, Local Group galaxy M31 was detected as a marginally extended gamma-ray source, while only an upper limit has been derived for the other nearby galaxy M33. We revisited the gamma-ray emission in the direction of M31 and M33 using more than 7 yr of LAT Pass 8 data in the energy range 0.1-100 GeV, presenting detailed morphological and spectral analyses. M33 remains undetected, and we computed an upper limit of 2.0 x 10(-12) erg cm(-2) s(-1) on the 0.1-100 GeV energy flux (95% confidence level). This revised upper limit remains consistent with the observed correlation between gamma-ray luminosity and star formation rate tracers and implies an average CR density in M33 that is at most half of that of the MW. M31 is detected with a significance of nearly 10 sigma. Its spectrum is consistent with a power law with photon index Gamma = 2.4 +/- 0.1(stat) (vertical bar) (syst) and a 0.1-100 GeV energy flux of (5.6 +/- 0.6(stat vertical bar syst)) x 10(-12) erg cm(-1) s(-1). M31 is detected to be extended with a 4 sigma significance. The spatial distribution of the emission is consistent with a uniform-brightness disk with a radius of 0 degrees.4 and no offset from the center of the galaxy, but nonuniform intensity distributions cannot be excluded. The flux from M31 appears confined to the inner regions of the galaxy and does not fill the disk of the galaxy or extend far from it. The gamma-ray signal is not correlated with regions rich in gas or star formation activity, which suggests that the emission is not interstellar in origin, unless the energetic particles radiating in gamma rays do not originate in recent star formation. Alternative and nonexclusive interpretations are that the emission results from a population of millisecond pulsar
Published: 2017
Full Text: View/download PDF

10. 3FHL : The Third Catalog of Hard Fermi-LAT Sources

Author: Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiaro, G., Ciprini, S., Cohen, J. M., Costantin, D., Costanza, F., Cuoco, A., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Dumora, D., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guillemot, L., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Horan, D., Johannesson, G., Kensei, S., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Loparco, F., Lott, B., Lubrano, P., Magill, J. D., Maldera, S., Manfreda, A., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Parkinson, P. M. Saz, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, M., Tak, D., Thayer, J. G., Thayer, J. B., Thompson, D. J., Torres, D. F., Torresi, E., Troja, E., Vianello, G., Wood, K., Wood, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiaro, G., Ciprini, S., Cohen, J. M., Costantin, D., Costanza, F., Cuoco, A., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Dumora, D., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Fortin, P., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guillemot, L., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Horan, D., Johannesson, G., Kensei, S., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Loparco, F., Lott, B., Lubrano, P., Magill, J. D., Maldera, S., Manfreda, A., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Palatiello, M., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Parkinson, P. M. Saz, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, M., Tak, D., Thayer, J. G., Thayer, J. B., Thompson, D. J., Torres, D. F., Torresi, E., Troja, E., Vianello, G., Wood, K., and Wood, M.
Abstract: We present a catalog of sources detected above 10 GeV by the Fermi Large Area Telescope (LAT) in the first 7 years of data using the Pass 8 event-level analysis. This is the Third Catalog of Hard Fermi-LAT Sources (3FHL), containing 1556 objects characterized in the 10 GeV-2 TeV energy range. The sensitivity and angular resolution are improved by factors of 3 and 2 relative to the previous LAT catalog at the same energies (1FHL). The vast majority of detected sources (79%) are associated with extragalactic counterparts at other wavelengths, including 16 sources located at very high redshift (z > 2). Of the sources, 8% have Galactic counterparts and 13% are unassociated (or associated with a source of unknown nature). The high-latitude sky and the Galactic plane are observed with a flux sensitivity of 4.4 to 9.5 x 10(-11) ph cm(-2) s(-1), respectively (this is approximately 0.5% and 1% of the Crab Nebula flux above 10 GeV). The catalog includes 214 new gamma-ray sources. The substantial increase in the number of photons (more than 4 times relative to 1FHL and 10 times to 2FHL) also allows us to measure significant spectral curvature for 32 sources and find flux variability for 163 of them. Furthermore, we estimate that for the same flux limit of 10(-12) erg cm(-2) s(-1), the energy range above 10 GeV has twice as many sources as the range above 50 GeV, highlighting the importance, for future Cherenkov telescopes, of lowering the energy threshold as much as possible.
Published: 2017
Full Text: View/download PDF

11. The Second Catalog of Flaring Gamma-Ray Sources from the Fermi All-sky Variability Analysis

Author: Abdollahi, S., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Chekhtman, A., Cheung, C. C., Chiaro, G., Ciprini, S., Conrad, Jan, Costantin, D., Costanza, F., Cutini, S., D'Ammando, F., de Palma, F., Desai, A., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Donaggio, B., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giomi, M., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hays, E., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kocevski, D., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, M., Tanaka, K., Thayer, J. B., Thompson, D. J., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Abdollahi, S., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Chekhtman, A., Cheung, C. C., Chiaro, G., Ciprini, S., Conrad, Jan, Costantin, D., Costanza, F., Cutini, S., D'Ammando, F., de Palma, F., Desai, A., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Donaggio, B., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giomi, M., Giordano, F., Giroletti, M., Glanzman, T., Green, D., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hays, E., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kocevski, D., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J. D., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paliya, V. S., Paneque, D., Perkins, J. S., Persic, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Porter, T. A., Principe, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, M., Tanaka, K., Thayer, J. B., Thompson, D. J., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Vianello, G., and Wood, K. S.
Abstract: We present the second catalog of flaring gamma-ray sources (2FAV) detected with the Fermi All-sky Variability Analysis (FAVA), a tool that blindly searches for transients over the entire sky observed by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope. With respect to the first FAVA catalog, this catalog benefits from a larger data set, the latest LAT data release (Pass 8), as well as from an improved analysis that includes likelihood techniques for a more precise localization of the transients. Applying this analysis to the first 7.4 years of Fermi observations, and in two separate energy bands 0.1-0.8 GeV and 0.8-300 GeV, a total of 4547 flares were detected with significance greater than 6s (before trials), on the timescale of one week. Through spatial clustering of these flares, 518 variable gamma-ray sources were identified. Based on positional coincidence, likely counterparts have been found for 441 sources, mostly among the blazar class of active galactic nuclei. For 77 2FAV sources, no likely gamma-ray counterpart has been found. For each source in the catalog, we provide the time, location, and spectrum of each flaring episode. Studying the spectra of the flares, we observe a harder-when-brighter behavior for flares associated with blazars, with the exception of BL Lac flares detected in the low-energy band. The photon indexes of the flares are never significantly smaller than 1.5. For a leptonic model, and under the assumption of isotropy, this limit suggests that the spectrum of freshly accelerated electrons is never harder than p similar to 2.
Published: 2017
Full Text: View/download PDF

12. Deep view of the Large Magellanic Cloud with six years of Fermi-LAT observations

Author: Ackermann, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Drell, P. S., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Godfrey, G., Grenier, I. A., Grondin, M. -H., Guillemot, L., Guiriec, S., Harding, A. K., Hill, A. B., Horan, D., Johannesson, G., Knoedlseder, J., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lubrano, P., Maldera, S., Martin, P., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Romani, R. W., Sánchez-Conde, Miguel, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, M., Zimmer, Stephan, Ackermann, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Drell, P. S., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Godfrey, G., Grenier, I. A., Grondin, M. -H., Guillemot, L., Guiriec, S., Harding, A. K., Hill, A. B., Horan, D., Johannesson, G., Knoedlseder, J., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lubrano, P., Maldera, S., Martin, P., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Romani, R. W., Sánchez-Conde, Miguel, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, M., and Zimmer, Stephan
Abstract: Context. The nearby Large Magellanic Cloud (LMC) provides a rare opportunity of a spatially resolved view of an external star-forming galaxy in gamma-rays. The LMC was detected at 0.1-100 GeV as an extended source with CGRO/EGRET and using early observations with the Fermi-LAT. The emission was found to correlate with massive star-forming regions and to be particularly bright towards 30 Doradus. Aims. Studies of the origin and transport of cosmic rays (CRs) in the Milky Way are frequently hampered by line-of-sight confusion and poor distance determination. The LMC offers a complementary way to address these questions by revealing whether and how the gamma-ray emission is connected to specific objects, populations of objects, and structures in the galaxy. Methods. We revisited the gamma-ray emission from the LMC using about 73 months of Fermi-LAT P7REP data in the 0.2-100 GeV range. We developed a complete spatial and spectral model of the LMC emission, for which we tested several approaches: a simple geometrical description, template-fitting, and a physically driven model for CR-induced interstellar emission. Results. In addition to identifying PSR J0540-6919 through its pulsations, we find two hard sources positionally coincident with plerion N 157B and supernova remnant N 132D, which were also detected at TeV energies with H.E.S.S. We detect an additional soft source that is currently unidentified. Extended emission dominates the total flux from the LMC. It consists of an extended component of about the size of the galaxy and additional emission from three to four regions with degree-scale sizes. If it is interpreted as CRs interacting with interstellar gas, the large-scale emission implies a large-scale population of similar to 1-100 GeV CRs with a density of similar to 30% of the local Galactic value. On top of that, the three to four small-scale emission regions would correspond to enhancements of the CR density by factors 2 to 6 or higher, possibly more energe
Published: 2016
Full Text: View/download PDF

13. FERMI LAT STACKING ANALYSIS OF SWIFT LOCALIZED GRBs

Author: Ackermann, M., Ajello, M., Anderson, B., Atwood, W. B., Axelsson, M., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bhat, P. N., Bissaldi, E., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Drell, P. S., Favuzzi, C., Focke, W. B., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hewitt, J. W., Hill, A. B., Horan, D., Johannesson, G., Kocevski, D., Kouveliotou, C., Kuss, M., Larsson, Stefan, Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Vianello, G., von Kienlin, A., Werner, M., Wood, K. S., Ackermann, M., Ajello, M., Anderson, B., Atwood, W. B., Axelsson, M., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bhat, P. N., Bissaldi, E., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Drell, P. S., Favuzzi, C., Focke, W. B., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hewitt, J. W., Hill, A. B., Horan, D., Johannesson, G., Kocevski, D., Kouveliotou, C., Kuss, M., Larsson, Stefan, Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Vianello, G., von Kienlin, A., Werner, M., and Wood, K. S.
Abstract: We perform a comprehensive stacking analysis of data collected by the Fermi. Large Area Telescope (LAT) of gamma-ray bursts (GRBs) localized by the Swift. spacecraft, which were not detected by the LAT but which fell within the instrument's field of view at the time of trigger. We examine a total of 79 GRBs by comparing the observed counts over a range of time intervals to that expected from designated background orbits, as well as by using a joint likelihood technique to model the expected distribution of stacked counts. We find strong evidence for subthreshold emission at MeV to GeV energies using both techniques. This observed excess is detected during intervals that include and exceed the durations typically characterizing the prompt emission observed at keV energies and lasts at least 2700 s after the co-aligned burst trigger. By utilizing a novel cumulative likelihood analysis, we find that although a burst's prompt gamma-ray and afterglow X-ray flux both correlate with the strength of the subthreshold emission, the X-ray afterglow flux measured by Swift's X-ray Telescope at 11 hr post trigger correlates far more significantly. Overall, the extended nature of the subthreshold emission and its connection to the burst's afterglow brightness lend. further support to the external forward shock origin of the late-time emission detected by the LAT. These results suggest that the extended high-energy emission observed by the LAT may be a relatively common feature but remains undetected in a majority of bursts owing. to instrumental threshold effects.
Published: 2016
Full Text: View/download PDF

14. DEVELOPMENT OF THE MODEL OF GALACTIC INTERSTELLAR EMISSION FOR STANDARD POINT-SOURCE ANALYSIS OF FERMI LARGE AREA TELESCOPE DATA

Author: Acero, F., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Harding, A. K., Hayashi, K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Hou, X., Jogler, T., Johannesson, G., Kamae, T., Kuss, M., Landriu, D., Larsson, Stefan, Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Martin, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Remy, Q., Renault, N., Sanchez-Conde, Miguel, Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Werner, M., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, Acero, F., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Harding, A. K., Hayashi, K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Hou, X., Jogler, T., Johannesson, G., Kamae, T., Kuss, M., Landriu, D., Larsson, Stefan, Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Martin, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Remy, Q., Renault, N., Sanchez-Conde, Miguel, Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Werner, M., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, Stephan
Abstract: Most of the celestial. rays detected by the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope originate from the interstellar medium when energetic cosmic rays interact with interstellar nucleons and photons. Conventional point-source and extended-source studies rely on the modeling of this diffuse emission for accurate characterization. Here, we describe the development of the Galactic Interstellar Emission Model (GIEM), which is the standard adopted by the LAT Collaboration and is publicly available. This model is based on a linear combination of maps for interstellar gas column density in Galactocentric annuli and for the inverse-Compton emission produced in the Galaxy. In the GIEM, we also include large-scale structures like Loop. I and the Fermi bubbles. The measured gas emissivity spectra confirm that the cosmic-ray proton density decreases with Galactocentric distance beyond 5 kpc from the Galactic Center. The measurements also suggest a softening of the proton spectrum with Galactocentric distance. We observe that the Fermi bubbles have boundaries with a shape similar to a catenary at latitudes below 20 degrees and we observe an enhanced emission toward their base extending in the north and south Galactic directions and located within similar to 4 degrees of the Galactic Center.
Published: 2016
Full Text: View/download PDF

15. FERMI-LAT OBSERVATIONS OF HIGH-ENERGY gamma-RAY EMISSION TOWARD THE GALACTIC CENTER

Author: Ajello, M., Albert, A., Atwood, W. B., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Carave, P. A., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Drell, P. S., Favuzzi, C., Ferrara, E. C., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Harding, A. K., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Karwin, C., Knoedlseder, J., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Malyshev, D., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sanchez-Conde, Miguel, Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Winer, B. L., Wood, K. S., Zaharijas, G., Zimmer, Stephan, Ajello, M., Albert, A., Atwood, W. B., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Carave, P. A., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Drell, P. S., Favuzzi, C., Ferrara, E. C., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Harding, A. K., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Karwin, C., Knoedlseder, J., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Malyshev, D., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sanchez-Conde, Miguel, Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Winer, B. L., Wood, K. S., Zaharijas, G., and Zimmer, Stephan
Abstract: The Fermi Large Area Telescope (LAT) has provided the most detailed view to date of the emission toward the Galactic center (GC) in high-energy gamma-rays. This paper describes the analysis of data taken during the first 62 months of the mission in the energy range 1-100 GeV from a 15 degrees x 15 degrees region about the direction of the GC. Specialized interstellar emission models (IEMs) are constructed to enable the separation of the.-ray emissions produced by cosmic ray particles interacting with the interstellar gas and radiation fields in the Milky Way into that from the inner similar to 1 kpc surrounding the GC, and that from the rest of the Galaxy. A catalog of point sources for the 15 degrees x 15 degrees region is self-consistently constructed using these IEMs: the First Fermi-LAT Inner Galaxy Point Source Catalog (1FIG). The spatial locations, fluxes, and spectral properties of the 1FIG sources are presented, and compared with gamma-ray point sources over the same region taken from existing catalogs. After subtracting the interstellar emission and point-source contributions a residual is found. If templates that peak toward the GC are used to model the positive residual the agreement with the data improves, but none of the additional templates tried account for all of its spatial structure. The spectrum of the positive residual modeled with these templates has a strong dependence on the choice of IEM.
Published: 2016
Full Text: View/download PDF

16. Search for Spectral Irregularities due to Photon-Axionlike-Particle Oscillations with the Fermi Large Area Telescope

Author: Ajello, M., Albert, A., Anderson, Brandon, Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Chekhtman, A., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Costanza, F., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Glanzman, T., Godfrey, G., Guiriec, S., Horan, D., Johannesson, G., Katsuragawa, M., Kensei, S., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Meyer, Manuel, Michelson, P. F., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nuss, E., Okada, C., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Sanchez-Conde, Miguel, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, Ajello, M., Albert, A., Anderson, Brandon, Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Chekhtman, A., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Costanza, F., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Glanzman, T., Godfrey, G., Guiriec, S., Horan, D., Johannesson, G., Katsuragawa, M., Kensei, S., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Meyer, Manuel, Michelson, P. F., Mirabal, N., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nuss, E., Okada, C., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Sanchez-Conde, Miguel, Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, Stephan
Abstract: We report on the search for spectral irregularities induced by oscillations between photons and axionlike-particles (ALPs) in the gamma-ray spectrum of NGC 1275, the central galaxy of the Perseus cluster. Using 6 years of Fermi Large Area Telescope data, we find no evidence for ALPs and exclude couplings above 5 x 10(-12) GeV-1 for ALP masses 0.5 less than or similar to m(a) less than or similar to 5 neV at 95% confidence. The limits are competitive with the sensitivity of planned laboratory experiments, and, together with other bounds, strongly constrain the possibility that ALPs can reduce the gamma-ray opacity of the Universe.
Published: 2016
Full Text: View/download PDF

17. 2FHL : THE SECOND CATALOG OF HARD FERMI-LAT SOURCES

Author: Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Cohen, J. M., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Franckowiak, A., Fukazawa, Y., Funk, S., Furniss, A. K., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H., Guillemot, L., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Iafrate, G., Hartmann, Dieter, Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Knoedlseder, J., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Li, Lang, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Romani, R. W., Sánchez-Conde, Miguel, Parkinson, P. M. Saz, Schmid, J., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, M., Takahashi, T., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Wood, M., Yassine, M., Zaharijas, G., Zimmer, Stephan, Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Cohen, J. M., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Franckowiak, A., Fukazawa, Y., Funk, S., Furniss, A. K., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H., Guillemot, L., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Iafrate, G., Hartmann, Dieter, Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Knoedlseder, J., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Li, Lang, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mirabal, N., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Romani, R. W., Sánchez-Conde, Miguel, Parkinson, P. M. Saz, Schmid, J., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, M., Takahashi, T., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Wood, M., Yassine, M., Zaharijas, G., and Zimmer, Stephan
Abstract: We present a catalog of sources detected above 50 GeV by the Fermi-Large Area Telescope (LAT) in 80 months of data. The newly delivered Pass. 8 event-level analysis allows the detection and characterization of sources in the 50 GeV-2 TeV energy range. In this energy band, Fermi-LAT. has detected 360 sources, which constitute the second catalog of hard Fermi-LAT. sources (2FHL). The improved angular resolution enables the precise localization of point sources (similar to 1.' 7 radius at 68% C.L.) and the detection and characterization of spatially extended sources. We find that 86% of the sources can be associated with counterparts at other wavelengths, of which the majority (75%) are active galactic nuclei and the rest (11%) are Galactic sources. Only 25% of the 2FHL sources have been previously detected by Cherenkov telescopes, implying that the 2FHL provides a reservoir of candidates to be followed up at very high energies. This work closes the energy gap between the observations performed at GeV energies by Fermi-LAT. on orbit and the observations performed at higher energies by Cherenkov telescopes from the ground.
Published: 2016
Full Text: View/download PDF

18. THE FIRST FERMI LAT SUPERNOVA REMNANT CATALOG

Author: Acero, F., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen, J. M., Cohen-Tanugi, J., Cominsky, L. R., Condon, B., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grondin, M. -H., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Hou, X., Iafrate, G., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Katsuta, J., Kerr, M., Knodlseder, J., Kocevski, D., Kuss, M., Laffon, H., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Li, Liang, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Marelli, M., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Renaud, M., Reposeur, T., Rousseau, R., Parkinson, P. M. Saz, Schmid, J., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Wells, B., Wood, K. S., Wood, M., Yassine, M., den Hartog, P. R., Zimmer, Stephan, Acero, F., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen, J. M., Cohen-Tanugi, J., Cominsky, L. R., Condon, B., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grondin, M. -H., Guillemot, L., Guiriec, S., Gustafsson, M., Hadasch, D., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Hou, X., Iafrate, G., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Katagiri, H., Kataoka, J., Katsuta, J., Kerr, M., Knodlseder, J., Kocevski, D., Kuss, M., Laffon, H., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Li, Liang, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Marelli, M., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Renaud, M., Reposeur, T., Rousseau, R., Parkinson, P. M. Saz, Schmid, J., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Wells, B., Wood, K. S., Wood, M., Yassine, M., den Hartog, P. R., and Zimmer, Stephan
Abstract: To uniformly determine the properties of supernova remnants (SNRs) at high energies, we have developed the first systematic survey at energies from 1 to 100 GeV using data from the Fermi Large Area Telescope (LAT). Based on the spatial overlap of sources detected at GeV energies with SNRs known from radio surveys, we classify 30 sources as likely GeV SNRs. We also report 14 marginal associations and 245 flux upper limits. A mock catalog in which the positions of known remnants are scrambled in Galactic longitude allows us to determine an upper limit of 22% on the number of GeV candidates falsely identified as SNRs. We have also developed a method to estimate spectral and spatial systematic errors arising from the diffuse interstellar emission model, a key component of all Galactic Fermi LAT analyses. By studying remnants uniformly in aggregate, we measure the GeV properties common to these objects and provide a crucial context for the detailed modeling of individual SNRs. Combining our GeV results with multiwavelength (MW) data, including radio, X-ray, and TeV, we demonstrate the need for improvements to previously sufficient, simple models describing the GeV and radio emission from these objects. We model the GeV and MW emission from SNRs in aggregate to constrain their maximal contribution to observed Galactic cosmic rays.
Published: 2016
Full Text: View/download PDF

19. FERMI-LAT OBSERVATIONS OF THE LIGO EVENT GW150914

Author: Ackermann, M., Ajello, M., Albert, A., Anderson, Brandon, Arimoto, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Condon, B., Costanza, F., Cuoco, A., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giomi, M., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Granot, J., Green, D., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Kamae, T., Kensei, S., Kocevski, D., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Magill, J., Maldera, S., Manfreda, A., Marelli, M., Mayer, M., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mirabal, N., Mizuno, T., Moiseev, A. A., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Rochester, L. S., Romani, R. W., Parkinson, P. M. Saz, Sgro, C., Simone, D., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Troja, E., Uchiyama, Y., Venters, T. M., Vianello, G., Wood, K. S., Wood, M., Zaharijas, G., Zhu, S., Zimmer, Stephan, Ackermann, M., Ajello, M., Albert, A., Anderson, Brandon, Arimoto, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Condon, B., Costanza, F., Cuoco, A., Cutini, S., D'Ammando, F., de Palma, F., Desiante, R., Digel, S. W., Di Lalla, N., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giomi, M., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Granot, J., Green, D., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Kamae, T., Kensei, S., Kocevski, D., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Lemoine-Goumard, M., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Magill, J., Maldera, S., Manfreda, A., Marelli, M., Mayer, M., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mirabal, N., Mizuno, T., Moiseev, A. A., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Rochester, L. S., Romani, R. W., Parkinson, P. M. Saz, Sgro, C., Simone, D., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Troja, E., Uchiyama, Y., Venters, T. M., Vianello, G., Wood, K. S., Wood, M., Zaharijas, G., Zhu, S., and Zimmer, Stephan
Abstract: The Fermi Large Area Telescope (LAT) has an instantaneous field of view (FoV) covering similar to 1/5 of the sky and it completes a survey of the entire sky in high-energy gamma-rays every 3 hr. It enables searches for transient phenomena over timescales from milliseconds to years. Among these phenomena could be electromagnetic counterparts to gravitational wave (GW) sources. In this paper, we present a detailed study of the LAT observations relevant to Laser Interferometer Gravitational-wave Observatory (LIGO) event GW150914, which is the first direct detection of gravitational waves and has been interpreted as being due to the coalescence of two stellar-mass black holes. The localization region for GW150914 was outside the LAT FoV at the time of the GW signal. However, as part of routine survey observations, the LAT observed the entire LIGO localization region within similar to 70 minutes of the trigger and thus enabled a comprehensive search for a.-ray counterpart to GW150914. The study of the LAT data presented here did not find any potential counterparts to GW150914, but it did provide limits on the presence of a transient counterpart above 100 MeV on timescales of hours to days over the entire GW150914 localization region.
Published: 2016
Full Text: View/download PDF

20. Search for gamma-ray emission from the Coma Cluster with six years of Fermi-LAT data

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, J., Cutini, S., D’Ammando, F., Angelis, A., de Palma, F., de Desiante, R., Digel, S. W., Venere, L., Di Drell, P. S., Favuzzi, C., Fegan, S. J., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Green, D., Grenier, I. A., Guiriec, S., Hays, E., Hewitt, J. W., Horan, D., JÃ³hannesson, G., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Rainó, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sánchez-Conde, Miguel, Sgró, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Zimmer, Stephan, Rephaeli, Y., Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, J., Cutini, S., D’Ammando, F., Angelis, A., de Palma, F., de Desiante, R., Digel, S. W., Venere, L., Di Drell, P. S., Favuzzi, C., Fegan, S. J., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Green, D., Grenier, I. A., Guiriec, S., Hays, E., Hewitt, J. W., Horan, D., JÃ³hannesson, G., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Rainó, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sánchez-Conde, Miguel, Sgró, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Zimmer, Stephan, and Rephaeli, Y.
Abstract: We present results from gamma-ray observations of the Coma cluster incorporating six years of Fermi-LAT data and the newly released "Pass 8" event-level analysis. Our analysis of the region reveals low-significance residual structures within the virial radius of the cluster that are too faint for a detailed investigation with the current data. Using a likelihood approach that is free of assumptions on the spectral shape we derive upper limits on the gamma-ray flux that is expected from energetic particle interactions in the cluster. We also consider a benchmark spatial and spectral template motivated by models in which the observed radio halo is mostly emission by secondary electrons. In this case, the median expected and observed upper limits for the flux above 100MeV are 1.7 x 10(-9) ph cm(-2) s(-1) and 5.2 x 10(-9) ph cm(-2) s(-1) respectively (the latter corresponds to residual emission at the level of 1.8 sigma). These bounds are comparable to or higher than predicted levels of hadronic gamma-ray emission in cosmic-ray (CR) models with or without reacceleration of secondary electrons, although direct comparisons are sensitive to assumptions regarding the origin and propagation mode of CRs and magnetic field properties. The minimal expected.-ray flux from radio and star-forming galaxies within the Coma cluster is roughly an order of magnitude below the median sensitivity of our analysis.
Published: 2016
Full Text: View/download PDF

21. Resolving the Extragalactic gamma-Ray Background above 50 GeV with the Fermi Large Area Telescope

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Costanza, F., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Green, D., Grenier, I. A., Guiriec, S., Hays, E., Horan, D., Iafrate, G., Jogler, T., Johannesson, G., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Magill, J., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nuss, E., Ohsugi, T., Okada, C., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Romani, R. W., Sanchez-Conde, Miguel, Schmid, J., Schulz, A., Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Yassine, M., Zimmer, Stephan, Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Cominsky, L. R., Costanza, F., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Mauro, M., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Green, D., Grenier, I. A., Guiriec, S., Hays, E., Horan, D., Iafrate, G., Jogler, T., Johannesson, G., Kuss, M., La Mura, G., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Magill, J., Maldera, S., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nuss, E., Ohsugi, T., Okada, C., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Romani, R. W., Sanchez-Conde, Miguel, Schmid, J., Schulz, A., Sgro, C., Simone, D., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Yassine, M., and Zimmer, Stephan
Abstract: The Fermi Large Area Telescope (LAT) Collaboration has recently released a catalog of 360 sources detected above 50 GeV (2FHL). This catalog was obtained using 80 months of data re-processed with Pass 8, the newest event-level analysis, which significantly improves the acceptance and angular resolution of the instrument. Most of the 2FHL sources at high Galactic latitude are blazars. Using detailed Monte Carlo simulations, we measure, for the first time, the source count distribution, dN= dS, of extragalactic.-ray sources at E > 50 GeV and find that it is compatible with a Euclidean distribution down to the lowest measured source flux in the 2FHL (8 x 10(-12) ph cm(-2) s(-1)). We employ a one-point photon fluctuation analysis to constrain the behavior of dN= dS below the source detection threshold. Overall, the source count distribution is constrained over three decades in flux and found compatible with a broken power law with a break flux, Sb, in the range [8 x 10-12; 1.5 x 10-11] ph cm(-2) s(-1) and power-law indices below and above the break of a 2. [1.60; 1.75] and a 1 +/- 2.49 +/- 0.12, respectively. Integration of dN= dS shows that point sources account for at least 86_16 -14 % of the total extragalactic gamma-ray background. The simple form of the derived source count distribution is consistent with a single population (i. e., blazars) dominating the source counts to the minimum flux explored by this analysis. We estimate the density of sources detectable in blind surveys that will be performed in the coming years by the Cherenkov Telescope Array.
Published: 2016
Full Text: View/download PDF

22. Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data

Author: Ackermann, M., Albert, A., Anderson, Brandon, Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Essig, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hays, E., Hewitt, J. W., Horan, D., Jogler, T., Johannesson, G., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., Li, Liang, Llena Garde, Maja, Longo, F., Loparco, F., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sánchez-Conde, Miguel, Schulz, A., Sehgal, N., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strigari, L., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, Ackermann, M., Albert, A., Anderson, Brandon, Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Essig, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hays, E., Hewitt, J. W., Horan, D., Jogler, T., Johannesson, G., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., Li, Liang, Llena Garde, Maja, Longo, F., Loparco, F., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sánchez-Conde, Miguel, Schulz, A., Sehgal, N., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strigari, L., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, Stephan
Abstract: The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on gamma-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new PASS8 event-level analysis. None of the dSphs are significantly detected in gamma rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. These constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass less than or similar to 100 GeV annihilating via quark and tau-lepton channels.
Published: 2015
Full Text: View/download PDF

23. Limits on dark matter annihilation signals from the Fermi LAT 4-year measurement of the isotropic gamma-ray background

Author: Ackermann, M., Ajello, M., Albert, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, Alessandro, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hou, X., Kamae, T., Kuss, M., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Massaro, F., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nemmen, R., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sánchez-Conde, Miguel, Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, Alessandro, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hou, X., Kamae, T., Kuss, M., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Massaro, F., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Negro, M., Nemmen, R., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sánchez-Conde, Miguel, Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., and Zaharijas, G.
Abstract: We search for evidence of dark matter (DM) annihilation in the isotropic gamma-ray background (IGRB) measured with 50 months of Fermi Large Area Telescope (LAT) observations. An improved theoretical description of the cosmological DM annihilation signal, based on two complementary techniques and assuming generic weakly interacting massive particle (WIMP) properties, renders more precise predictions compared to previous work. More specifically, we estimate the cosmologically-induced gamma-ray intensity to have an uncertainty of a factor similar to 20 in canonical setups. We consistently include both the Galactic and extragalactic signals under the same theoretical framework, and study the impact of the former on the IGRB spectrum derivation. We find no evidence for a DM signal and we set limits on the DM-induced isotropic gamma-ray signal. Our limits are competitive for DM particle masses up to tens of TeV and, indeed, are the strongest limits derived from Fermi LAT data at TeV energies. This is possible thanks to the new Fermi LAT IGRB measurement, which now extends up to an energy of 820 GeV. We quantify uncertainties in detail and show the potential this type of search offers for testing the WIMP paradigm with a complementary and truly cosmological probe of DM particle signals.
Published: 2015
Full Text: View/download PDF

24. THE SPECTRUM OF ISOTROPIC DIFFUSE GAMMA-RAY EMISSION BETWEEN 100 MeV AND 820 GeV

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashi, K., Hays, E., Hewitt, J. W., Ippoliti, P., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Knoedlseder, J., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., EGENLi, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Manfreda, A., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romani, R. W., Sanchez-Conde, M., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., do Couto e Silva, E., Drell, P. S., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashi, K., Hays, E., Hewitt, J. W., Ippoliti, P., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Knoedlseder, J., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., EGENLi, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Manfreda, A., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romani, R. W., Sanchez-Conde, M., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, Stephan
Abstract: The gamma-ray sky can be decomposed into individually detected sources, diffuse emission attributed to the interactions of Galactic cosmic rays with gas and radiation fields, and a residual all-sky emission component commonly called the isotropic diffuse gamma-ray background (IGRB). The IGRB comprises all extragalactic emissions too faint or too diffuse to be resolved in a given survey, as well as any residual Galactic foregrounds that are approximately isotropic. The first IGRB measurement with the Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope (Fermi) used 10 months of sky-survey data and considered an energy range between 200 MeV and 100 GeV. Improvements in event selection and characterization of cosmic-ray backgrounds, better understanding of the diffuse Galactic emission (DGE), and a longer data accumulation of 50 months allow for a refinement and extension of the IGRB measurement with the LAT, now covering the energy range from 100 MeV to 820 GeV. The IGRB spectrum shows a significant high-energy cutoff feature and can be well described over nearly four decades in energy by a power law with exponential cutoff having a spectral index of 2.32 +/- 0.02 and a break energy of (279 +/- 52) GeV using our baseline DGE model. The total intensity attributed to the IGRB is (7.2 +/- 0.6) x 10(-6) cm(-2) s(-1) sr(-1) above 100 MeV, with an additional +15%/-30% systematic uncertainty due to the Galactic diffuse foregrounds., AuthorCount:144
Published: 2015
Full Text: View/download PDF

25. FERMI LARGE AREA TELESCOPE THIRD SOURCE CATALOG

Author: Acero, F., Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Belfiore, A., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bogart, J. R., Bonino, R., Bottacini, E., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Charles, E., Chaves, R. C. G., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., DeKlotz, M., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giebels, B., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Iafrate, G., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Kataoka, J., Katsuta, J., Kuss, M., La Mura, G., Landriu, D., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mirabal, N., Mizuno, T., Moiseev, A. A., Mongelli, M., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Rochester, L. S., Romani, R. W., Salvetti, D., Sanchez-Coude, Miguel, Parkinson, P. M. Saz, Schulz, A., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Stephens, T. E., Strong, A. W., Suson, D. J., Takahashi, H., Takahashi, T., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Van Klaveren, B., Vianello, G., Winer, B. L., Wood, K. S., Wood, M., Zimmer, Stephan, Acero, F., Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Belfiore, A., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bogart, J. R., Bonino, R., Bottacini, E., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Charles, E., Chaves, R. C. G., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., DeKlotz, M., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giebels, B., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Iafrate, G., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Kataoka, J., Katsuta, J., Kuss, M., La Mura, G., Landriu, D., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mirabal, N., Mizuno, T., Moiseev, A. A., Mongelli, M., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Rochester, L. S., Romani, R. W., Salvetti, D., Sanchez-Coude, Miguel, Parkinson, P. M. Saz, Schulz, A., Siskind, E. J., Smith, D. A., Spada, F., Spandre, G., Spinelli, P., Stephens, T. E., Strong, A. W., Suson, D. J., Takahashi, H., Takahashi, T., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Van Klaveren, B., Vianello, G., Winer, B. L., Wood, K. S., Wood, M., and Zimmer, Stephan
Abstract: We present the third Fermi Large Area Telescope (LAT) source catalog (3FGL) of sources in the 100 MeV-300 GeV range. Based on the first 4 yr of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this energy range. Relative to the Second Fermi LAT catalog, the 3FGL catalog incorporates twice as much data, as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse.-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The 3FGL catalog includes 3033 sources above 4 sigma significance, with source location regions, spectral properties, and monthly light curves for each. Of these, 78 are flagged as potentially being due to imperfections in the model for Galactic diffuse emission. Twenty-five sources are modeled explicitly as spatially extended, and overall 238 sources are considered as identified based on angular extent or correlated variability (periodic or otherwise) observed at other wavelengths. For 1010 sources we have not found plausible counterparts at other wavelengths. More than 1100 of the identified or associated sources are active galaxies of the blazar class; several other classes of non-blazar active galaxies are also represented in the 3FGL. Pulsars represent the largest Galactic source class. From source counts of Galactic sources we estimate that the contribution of unresolved sources to the Galactic diffuse emission is similar to 3% at 1 GeV.
Published: 2015
Full Text: View/download PDF

26. Updated search for spectral lines from Galactic dark matter interactions with pass 8 data from the Fermi Large Area Telescope

Author: Ackermann, M., Ajello, M., Albert, A., Anderson, Brandon, Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grove, J. E., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hill, A. B., Horan, D., Johannesson, G., Johnson, R. P., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Reimer, A., Reposeur, T., Ritz, S., Sanchez-Coude, Miguel, Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, Ackermann, M., Ajello, M., Albert, A., Anderson, Brandon, Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grove, J. E., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hill, A. B., Horan, D., Johannesson, G., Johnson, R. P., Kuss, M., Larsson, Stefan, Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Reimer, A., Reposeur, T., Ritz, S., Sanchez-Coude, Miguel, Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, Stephan
Abstract: Dark matter in the Milky Way may annihilate directly into. rays, producing a monoenergetic spectral line. Therefore, detecting such a signature would be strong evidence for dark matter annihilation or decay. We search for spectral lines in the Fermi Large Area Telescope observations of the Milky Way halo in the energy range 200 MeV-500 GeV using analysis methods from our most recent line searches. The main improvements relative to previous works are our use of 5.8 years of data reprocessed with the Pass 8 event-level analysis and the additional data resulting from the modified observing strategy designed to increase exposure of the Galactic center region. We search in five sky regions selected to optimize sensitivity to different theoretically motivated dark matter scenarios and find no significant detections. In addition to presenting the results from our search for lines, we also investigate the previously reported tentative detection of a line at 133 GeV using the new Pass 8 data.
Published: 2015
Full Text: View/download PDF

27. GAMMA-RAY FLARING ACTIVITY FROM THE GRAVITATIONALLY LENSED BLAZAR PKS 1830-211 OBSERVED BY Fermi LAT

Author: Abdo, A. A., Ackermann, M., Ajello, M., Allafort, A., Amin, M. A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Buehler, R., Bulmash, D., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Corbet, R. H. D., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Finke, J., Focke, W. B., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., Mehault, J., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ritz, S., Romoli, C., Roth, M., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Takeuchi, Y., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Werner, M., Winer, B. L., Wood, K. S., Abdo, A. A., Ackermann, M., Ajello, M., Allafort, A., Amin, M. A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bonamente, E., Borgland, A. W., Bregeon, J., Brigida, M., Buehler, R., Bulmash, D., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Corbet, R. H. D., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Finke, J., Focke, W. B., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mazziotta, M. N., Mehault, J., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ritz, S., Romoli, C., Roth, M., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Takeuchi, Y., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Werner, M., Winer, B. L., and Wood, K. S.
Abstract: The Large Area Telescope ( LAT) on board the FermiGamma- ray Space Telescope routinely detects the MeV- peaked flat- spectrum radio quasar PKS 1830- 211 ( z = 2.507). Its apparent isotropic. - ray luminosity ( E > 100 MeV), averaged over 3 years of observations and peaking on 2010 October 14/ 15 at 2.9 x 1050 erg s- 1, makes it among the brightest high- redshift Fermi blazars. No published model with a single lens can account for all of the observed characteristics of this complex system. Based on radio observations, one expects time- delayed variability to follow about 25 days after a primary flare, with flux about a factor of 1.5 less. Two large. - ray flares of PKS 1830- 211 have been detected by the LAT in the considered period, and no substantial evidence for such a delayed activity was found. This allows us to place a lower limit of about 6 on the. - ray flux ratio between the two lensed images. Swift XRT observations from a dedicated Target of Opportunity program indicate a hard spectrum with no significant correlation of X- ray flux with the. - ray variability. The spectral energy distribution can be modeled with inverse Compton scattering of thermal photons from the dusty torus. The implications of the LAT data in terms of variability, the lack of evident delayed flare events, and different radio and. - ray flux ratios are discussed. Microlensing effects, absorption, size and location of the emitting regions, the complex mass distribution of the system, an energy- dependent inner structure of the source, and flux suppression by the lens galaxy for one image path may be considered as hypotheses for understanding our results., AuthorCount:128
Published: 2015
Full Text: View/download PDF

28. THE THIRD CATALOG OF ACTIVE GALACTIC NUCLEI DETECTED BY THE FERMI LARGE AREA TELESCOPE

Author: Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bialdi, E., Blandford, R. D., Bloom, E. D., Bnino, R., Bottagini, E., Brandt, T. J., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Careenter, B., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Abrusco, R., D'Ammando, F., de Angelis, A., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Focke, W. B., Franckowiak, A., Fuhrmann, L., Fukazawa, Y., Furniss, A. K., Fusco, P., Gargano, E., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, E., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hewitt, J. W., Hill, A. B., Horan, D., Itoh, R., Jóhannesson, G., Johnson, A. S., Johnson, W. N., Kataoka, J., Kawano, T., Krauss, F., Kuss, M., La Mura, G., Larsson, Stefan, Latronico, L., Leto, C., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Oxsugi, T., Ojha, R., Omdei, N., Orienti, M., Orlando, E., Paggi, A., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romani, R. W., Salvetti, D., Schaal, M., Schinzel, F. K., Schulz, A., Sgrò, C., Siskind, E. J., Sokolovsky, K. V., Spada, F., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, H., Takahashi, T., Tanaka, Y., Thayer, J. G., Thayer, J. B., Tibaldo, L., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Winer, B. L., Wood, K. S., Zimmer, Stephan, Ackermann, M., Ajello, M., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Gonzalez, J. Becerra, Bellazzini, R., Bialdi, E., Blandford, R. D., Bloom, E. D., Bnino, R., Bottagini, E., Brandt, T. J., Bregeon, J., Britto, R. J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Careenter, B., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Abrusco, R., D'Ammando, F., de Angelis, A., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Focke, W. B., Franckowiak, A., Fuhrmann, L., Fukazawa, Y., Furniss, A. K., Fusco, P., Gargano, E., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, E., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hewitt, J. W., Hill, A. B., Horan, D., Itoh, R., Jóhannesson, G., Johnson, A. S., Johnson, W. N., Kataoka, J., Kawano, T., Krauss, F., Kuss, M., La Mura, G., Larsson, Stefan, Latronico, L., Leto, C., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Oxsugi, T., Ojha, R., Omdei, N., Orienti, M., Orlando, E., Paggi, A., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romani, R. W., Salvetti, D., Schaal, M., Schinzel, F. K., Schulz, A., Sgrò, C., Siskind, E. J., Sokolovsky, K. V., Spada, F., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, H., Takahashi, T., Tanaka, Y., Thayer, J. G., Thayer, J. B., Tibaldo, L., Torres, D. F., Torresi, E., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Winer, B. L., Wood, K. S., and Zimmer, Stephan
Abstract: The third catalog of active galactic nuclei (AGNs) detected by the Fermi-LAT (3LAC) is presented. It is based on the third Fermi-LAT catalog (3FGL) of sources detected between 100 MeV and 300 GeV with a Test Statistic greater than 25, between 2008 August 4 and 2012 July 31. The 3LAC includes 1591 AGNs located at high Galactic latitudes (vertical bar b vertical bar > 10 degrees), a 71% increase over the second catalog based on 2 years of data. There are 28 duplicate associations, thus 1563 of the 2192 high-latitude gamma-ray sources of the 3FGL catalog are AGNs. Most of them (98%) are blazars. About half of the newly detected blazars are of unknown type, i.e., they lack spectroscopic information of sufficient quality to determine the strength of their emission lines. Based on their gamma-ray spectral properties, these sources are evenly split between flat-spectrum radio quasars (FSRQs) and BL Lacs. The most abundant detected BL Lacs are of the high-synchrotron-peaked (HSP) type. About 50% of the BL Lacs have no measured redshifts. A few new rare outliers (HSP-FSRQs and high-luminosity HSP BL Lacs) are reported. The general properties of the 3LAC sample confirm previous findings from earlier catalogs. The fraction of 3LAC blazars in the total population of blazars listed in BZCAT remains non-negligible even at the faint ends of the BZCAT-blazar radio, optical, and X-ray flux distributions, which hints that even the faintest known blazars could eventually shine in gamma-rays at LAT-detection levels. The energy-flux distributions of the different blazar populations are in good agreement with extrapolation from earlier catalogs.
Published: 2015
Full Text: View/download PDF

29. SEARCH FOR EARLY GAMMA-RAY PRODUCTION IN SUPERNOVAE LOCATED IN A DENSE CIRCUMSTELLAR MEDIUM WITH THE FERMI LAT

Author: Ackermann, M., Arcavi, I., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Franckowiak, A., Funk, S., Fusco, P., Gal-Yam, A., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Harding, A. K., Hayashi, K., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Kocevski, D., Kuss, M., Larsson, Stefan, Lashner, J., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murase, K., Nugent, P., Nuss, E., Ofek, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Werner, M., Wood, K. S., Wood, M., Ackermann, M., Arcavi, I., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Franckowiak, A., Funk, S., Fusco, P., Gal-Yam, A., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Harding, A. K., Hayashi, K., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Kocevski, D., Kuss, M., Larsson, Stefan, Lashner, J., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Murase, K., Nugent, P., Nuss, E., Ofek, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Werner, M., Wood, K. S., and Wood, M.
Abstract: Supernovae (SNe) exploding in a dense circumstellar medium (CSM) are hypothesized to accelerate cosmic rays in collisionless shocks and emit GeV gamma-rays and TeV neutrinos on a timescale of several months. We perform the first systematic search for gamma-ray emission in Fermi Large Area Telescope data in the energy range from 100 MeV to 300 GeV from the ensemble of 147 SNe Type IIn exploding in a dense CSM. We search for a gamma-ray excess at each SNe location in a one-year time window. In order to enhance a possible weak signal, we simultaneously study the closest and optically brightest sources of our sample in a joint-likelihood analysis in three different time windows (1 year, 6 months, and 3 months). For the most promising source of the sample, SN 2010jl (PTF 10aaxf), we repeat the analysis with an extended time window lasting 4.5 years. We do not find a significant excess in gamma-rays for any individual source nor for the combined sources and provide model-independent flux upper limits for both cases. In addition, we derive limits on the gamma-ray luminosity and the ratio of gamma-ray-to-optical luminosity ratio as a function of the index of the proton injection spectrum assuming a generic gamma-ray production model. Furthermore, we present detailed flux predictions based on multi-wavelength observations and the corresponding flux upper limit at a 95% confidence level (CL) for the source SN 2010jl (PTF 10aaxf).
Published: 2015
Full Text: View/download PDF

30. Searching for Dark Matter Annihilation from Milky Way Dwarf Spheroidal Galaxies with Six Years of Fermi Large Area Telescope Data

Author: Ackermann, M., Albert, A., Anderson, Brandon, Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Essig, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hays, E., Hewitt, J. W., Horan, D., Jogler, T., Johannesson, G., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Llena Garde, Maja, Longo, F., Loparco, F., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sánchez-Conde, Miguel, Schulz, A., Sehgal, N., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strigari, L., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, Ackermann, M., Albert, A., Anderson, Brandon, Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cuoco, A., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Essig, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hays, E., Hewitt, J. W., Horan, D., Jogler, T., Johannesson, G., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Llena Garde, Maja, Longo, F., Loparco, F., Lubrano, P., Malyshev, D., Mayer, M., Mazziotta, M. N., McEnery, J. E., Meyer, Manuel, Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Sánchez-Conde, Miguel, Schulz, A., Sehgal, N., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Strigari, L., Tajima, H., Takahashi, H., Thayer, J. B., Tibaldo, L., Torres, D. F., Troja, E., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., and Zimmer, Stephan
Abstract: The dwarf spheroidal satellite galaxies (dSphs) of the Milky Way are some of the most dark matter (DM) dominated objects known. We report on gamma-ray observations of Milky Way dSphs based on six years of Fermi Large Area Telescope data processed with the new PASS8 event-level analysis. None of the dSphs are significantly detected in gamma rays, and we present upper limits on the DM annihilation cross section from a combined analysis of 15 dSphs. These constraints are among the strongest and most robust to date and lie below the canonical thermal relic cross section for DM of mass less than or similar to 100 GeV annihilating via quark and tau-lepton channels.
Published: 2015
Full Text: View/download PDF

31. MULTIWAVELENGTH EVIDENCE FOR QUASI-PERIODIC MODULATION IN THE GAMMA-RAY BLAZAR PG 1553+113

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fuhrmann, L., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Green, D., Grenier, I. A., Grove, J. E., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Manfreda, A., Max-Moerbeck, W., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Ojha, R., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Pearson, T. J., Perkins, J. S., Perri, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Readhead, A., Reimer, A., Reimer, O., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Wood, K. S., Wood, M., Zimmer, Stephan, Berdyugin, A., Corbet, R. H. D., Hovatta, T., Lindfors, E., Nilsson, K., Reinthal, R., Sillanpaa, A., Stamerra, A., Takalo, L. O., Valtonen, M. J., Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Becerra Gonzalez, J., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bonino, R., Bottacini, E., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Di Venere, L., Dominguez, A., Drell, P. S., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fuhrmann, L., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Green, D., Grenier, I. A., Grove, J. E., Guiriec, S., Harding, A. K., Hays, E., Hewitt, J. W., Hill, A. B., Horan, D., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Magill, J., Maldera, S., Manfreda, A., Max-Moerbeck, W., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohno, M., Ohsugi, T., Ojha, R., Omodei, N., Orlando, E., Ormes, J. F., Paneque, D., Pearson, T. J., Perkins, J. S., Perri, M., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Readhead, A., Reimer, A., Reimer, O., Schulz, A., Sgro, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Wood, K. S., Wood, M., Zimmer, Stephan, Berdyugin, A., Corbet, R. H. D., Hovatta, T., Lindfors, E., Nilsson, K., Reinthal, R., Sillanpaa, A., Stamerra, A., Takalo, L. O., and Valtonen, M. J.
Abstract: We report for the first time a gamma-ray and multiwavelength nearly periodic oscillation in an active galactic nucleus. Using the Fermi Large Area Telescope we have discovered an apparent quasi-periodicity in the gamma-ray flux (E > 100 MeV) from the GeV/TeV BL Lac object PG 1553+113. The marginal significance of the 2.18 +/- 0.08 year period gamma-ray cycle is strengthened by correlated oscillations observed in radio and optical fluxes, through data collected in the Owens Valley Radio Observatory, Tuorla, Katzman Automatic Imaging Telescope, and Catalina Sky Survey monitoring programs and Swift-UVOT. The optical cycle appearing in similar to 10 years of data has a similar period, while the 15 GHz oscillation is less regular than seen in the other bands. Further long-term multiwavelength monitoring of this blazar may discriminate among the possible explanations for this quasi-periodicity.
Published: 2015
Full Text: View/download PDF

32. Search for extended gamma-ray emission from the Virgo Galaxy Cluster with Fermi-LAT

Author: Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D’Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hill, A. B., Horan, D., Jeltema, T. E., Jogler, T., Johnson, A. S., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sánchez-Conde, Miguel, Schulz, A., Sgró, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Storm, E., Tajima, H., Takahashi, H., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, Pinzke, Anders, Ackermann, M., Ajello, M., Albert, A., Atwood, W. B., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bloom, E. D., Bonino, R., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caputo, R., Caragiulo, M., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiaro, G., Ciprini, S., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D’Ammando, F., de Angelis, A., de Palma, F., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hewitt, J. W., Hill, A. B., Horan, D., Jeltema, T. E., Jogler, T., Johnson, A. S., Kuss, M., Larsson, S., Latronico, L., Li, J., Li, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Maldera, S., Malyshev, D., Manfreda, A., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Rainò, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Sánchez-Conde, Miguel, Schulz, A., Sgró, C., Siskind, E. J., Spada, F., Spandre, G., Spinelli, P., Storm, E., Tajima, H., Takahashi, H., Thayer, J. B., Torres, D. F., Tosti, G., Troja, E., Vianello, G., Wood, K. S., Wood, M., Zaharijas, G., Zimmer, Stephan, and Pinzke, Anders
Abstract: Galaxy clusters are one of the prime sites to search for dark matter (DM) annihilation signals. Depending on the substructure of the DM halo of a galaxy cluster and the cross sections for DM annihilation channels, these signals might be detectable by the latest generation of gamma-ray telescopes. Here we use three years of Fermi-Large Area Telescope data, which are the most suitable for searching for very extended emission in the vicinity of the nearby Virgo galaxy cluster. Our analysis reveals statistically significant extended emission which can be well characterized by a uniformly emitting disk profile with a radius of 3 degrees that moreover is offset from the cluster center. We demonstrate that the significance of this extended emission strongly depends on the adopted interstellar emission model (IEM) and is most likely an artifact of our incomplete description of the IEM in this region. We also search for and find new point source candidates in the region. We then derive conservative upper limits on the velocity-averaged DM pair annihilation cross section from Virgo. We take into account the potential gamma-ray flux enhancement due to DM sub-halos and its complex morphology as a merging cluster. For DM annihilating into b (b) over bar, assuming a conservative sub-halo model setup, we find limits that are between 1 and 1.5 orders of magnitude above the expectation from the thermal cross section for m(DM) <= 100 GeV. In a more optimistic scenario, we exclude similar to 3 x 10(-26)cm(3)s(-1) for m(DM)less than or similar to 40 GeV for the same channel. Finally, we derive upper limits on the gamma-ray-flux produced by hadronic cosmic-ray interactions in the inter cluster medium. We find that the volume-averaged cosmic-ray-to-thermal pressure ratio is less than similar to 6%.
Published: 2015
Full Text: View/download PDF

33. IMPULSIVE AND LONG DURATION HIGH-ENERGY GAMMA-RAY EMISSION FROM THE VERY BRIGHT 2012 MARCH 7 SOLAR FLARES

Author: Ajello, M., Albert, A., Allafort, A., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bonamente, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Murphy, R., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Roth, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, D. L., Wood, K. S., Yang, Zhaoyu, Ajello, M., Albert, A., Allafort, A., Baldini, L., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bonamente, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Murphy, R., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Roth, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, D. L., Wood, K. S., and Yang, Zhaoyu
Abstract: The Fermi Large Area Telescope (LAT) detected gamma-rays up to 4 GeV from two bright X-class solar flares on 2012 March 7, showing both an impulsive and temporally extended emission phases. The gamma-rays appear to originate from the same active region as the X-rays associated with these flares. The >100 MeV gamma-ray flux decreases monotonically during the first hour (impulsive phase) followed by a slower decrease for the next 20 hr. A power law with a high-energy exponential cutoff can adequately describe the photon spectrum. Assuming that the gamma rays result from the decay of pions produced by accelerated protons and ions with a power-law spectrum, we find that the index of that spectrum is similar to 3, with minor variations during the impulsive phase. During the extended phase the photon spectrum softens monotonically, requiring the proton index varying from similar to 4 to >5. The >30 MeV proton flux observed by the GOES satellites also shows a flux decrease and spectral softening, but with a harder spectrum (index similar to 2-3). Based on these observations, we explore the relative merits of prompt or continuous acceleration scenarios, hadronic or leptonic emission processes, and acceleration at the solar corona or by the fast coronal mass ejections. We conclude that the most likely scenario is continuous acceleration of protons in the solar corona that penetrate the lower solar atmosphere and produce pions that decay into gamma rays. However, acceleration in the downstream of the shock cannot be definitely ruled out., AuthorCount:136
Published: 2014
Full Text: View/download PDF

34. Inferred Cosmic-Ray Spectrum from Fermi Large Area Telescope gamma-Ray Observations of Earth's Limb

Author: Ackermann, M., Ajello, M., Albert, A., Allafort, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Bouvier, A., Brandt, T. J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grove, J. E., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hewitt, J. W., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Knödlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Yang, Z., Ackermann, M., Ajello, M., Albert, A., Allafort, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Bouvier, A., Brandt, T. J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Grove, J. E., Guiriec, S., Gustafsson, M., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hewitt, J. W., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Knödlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Strong, A. W., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Wood, M., and Yang, Z.
Abstract: Recent accurate measurements of cosmic-ray (CR) species by ATIC-2, CREAM, and PAMELA reveal an unexpected hardening in the proton and He spectra above a few hundred GeV, a gradual softening of the spectra just below a few hundred GeV, and a harder spectrum of He compared to that of protons. These newly discovered features may offer a clue to the origin of high-energy CRs. We use the Fermi Large Area Telescope observations of the gamma-ray emission from Earth's limb for an indirect measurement of the local spectrum of CR protons in the energy range similar to 90 GeV-6 TeV (derived from a photon energy range 15 GeV-1 TeV). Our analysis shows that single power law and broken power law spectra fit the data equally well and yield a proton spectrum with index 2.68 +/- 0.04 and 2.61 +/- 0.08 above similar to 200 GeV, respectively., AuthorCount:152
Published: 2014
Full Text: View/download PDF

35. Fermi-LAT Observations of the Gamma-Ray Burst GRB 130427A

Author: Ackermann, M., Ajello, M., Asano, K., Atwood, W. B., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgess, J. Michael, Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chaplin, V., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cleveland, W., Cohen-Tanugi, J., Collazzi, A., Cominsky, L. R., Connaughton, V., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., DeKlotz, M., de Palma, F., Dermer, C. D., Desiante, R., Diekmann, A., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Fitzpatrick, G., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Gibby, M., Giglietto, N., Giles, M., Giordano, F., Giroletti, M., Godfrey, G., Granot, J., Grenier, I. A., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Inoue, Y., Jogler, T., Johannesson, G., Johnson, W. N., Kawano, T., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Paneque, D., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Ryde, F., Sartori, A., Parkinson, P. M. Saz, Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Yamazaki, R., Younes, G., Yu, H. -F, Zhu, S. J., Bhat, P. N., Briggs, M. S., Byrne, D., Foley, S., Goldstein, A., Jenke, P., Kippen, R. M., Kouveliotou, C., McBreen, S., Meegan, C., Paciesas, W. S., Preece, R., Rau, A., Tierney, D., van der Horst, A. J., von Kienlin, A., Wilson-Hodge, C., Xiong, S., Cusumano, G., La Parola, V., Cummings, J. R., Ackermann, M., Ajello, M., Asano, K., Atwood, W. B., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgess, J. Michael, Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chaplin, V., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cleveland, W., Cohen-Tanugi, J., Collazzi, A., Cominsky, L. R., Connaughton, V., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., DeKlotz, M., de Palma, F., Dermer, C. D., Desiante, R., Diekmann, A., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Finke, J., Fitzpatrick, G., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Gibby, M., Giglietto, N., Giles, M., Giordano, F., Giroletti, M., Godfrey, G., Granot, J., Grenier, I. A., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Inoue, Y., Jogler, T., Johannesson, G., Johnson, W. N., Kawano, T., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Paneque, D., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Ryde, F., Sartori, A., Parkinson, P. M. Saz, Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Yamazaki, R., Younes, G., Yu, H. -F, Zhu, S. J., Bhat, P. N., Briggs, M. S., Byrne, D., Foley, S., Goldstein, A., Jenke, P., Kippen, R. M., Kouveliotou, C., McBreen, S., Meegan, C., Paciesas, W. S., Preece, R., Rau, A., Tierney, D., van der Horst, A. J., von Kienlin, A., Wilson-Hodge, C., Xiong, S., Cusumano, G., La Parola, V., and Cummings, J. R.
Abstract: The observations of the exceptionally bright gamma-ray burst (GRB) 130427A by the Large Area Telescope aboard the Fermi Gamma-ray Space Telescope provide constraints on the nature of these unique astrophysical sources. GRB 130427A had the largest fluence, highest-energy photon (95 GeV), longest gamma-ray duration (20 hours), and one of the largest isotropic energy releases ever observed from a GRB. Temporal and spectral analyses of GRB 130427A challenge the widely accepted model that the nonthermal high-energy emission in the afterglow phase of GRBs is synchrotron emission radiated by electrons accelerated at an external shock., AuthorCount:182
Published: 2014
Full Text: View/download PDF

36. Fermi establishes classical novae as a distinct class of gamma-ray sources

Author: Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Corbel, S., D'Ammando, F., de Angelis, A., den Hartog, P. R., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., do Couto e Silva, E., Donato, D., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fuhrmann, L., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J. W., Hill, A. B., Hou, X., Jean, P., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kerr, M., Knoedlseder, J., Kuss, M., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Manfreda, A., Martin, P., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Parkinson, P. M. Saz, Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Wood, M., Charbonnel, S., Corbet, R. H. D., Aquino, I. De Gennaro, Edlin, J. P., Mason, E., Schwarz, G. J., Shore, S. N., Starrfield, S., Teyssier, F., Ackermann, M., Ajello, M., Albert, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Corbel, S., D'Ammando, F., de Angelis, A., den Hartog, P. R., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., do Couto e Silva, E., Donato, D., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fuhrmann, L., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J. W., Hill, A. B., Hou, X., Jean, P., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kerr, M., Knoedlseder, J., Kuss, M., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Manfreda, A., Martin, P., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Parkinson, P. M. Saz, Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, L., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Wood, M., Charbonnel, S., Corbet, R. H. D., Aquino, I. De Gennaro, Edlin, J. P., Mason, E., Schwarz, G. J., Shore, S. N., Starrfield, S., and Teyssier, F.
Abstract: A classical nova results from runaway thermonuclear explosions on the surface of a white dwarf that accretes matter from a low-mass main-sequence stellar companion. In 2012 and 2013, three novae were detected in gamma rays and stood in contrast to the first gamma-ray-detected nova V407 Cygni 2010, which belongs to a rare class of symbiotic binary systems. Despite likely differences in the compositions and masses of their white dwarf progenitors, the three classical novae are similarly characterized as soft-spectrum transient gamma-ray sources detected over 2- to 3-week durations. The gamma-ray detections point to unexpected high-energy particle acceleration processes linked to the mass ejection from thermonuclear explosions in an unanticipated class of Galactic gamma-ray sources., AuthorCount:154
Published: 2014
Full Text: View/download PDF

37. THE SPECTRUM AND MORPHOLOGY OF THE FERMI BUBBLES

Author: Ackermann, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., do Couto e Silva, E., Drell, P. S., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Hadasch, D., Harding, A. K., Hays, E., Hewitt, J. W., Hou, X., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Knoedlseder, J., Kocevski, D., Kuss, M., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Manfreda, A., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sanchez-Conde, M., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, Lukasz, Strong, A. W., Suson, D. J., Tahara, M., Takahashi, H., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Zaharijas, G., Ackermann, M., Albert, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bissaldi, E., Blandford, R. D., Bloom, E. D., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caragiulo, M., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., do Couto e Silva, E., Drell, P. S., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Hadasch, D., Harding, A. K., Hays, E., Hewitt, J. W., Hou, X., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Knoedlseder, J., Kocevski, D., Kuss, M., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Malyshev, D., Manfreda, A., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Sanchez-Conde, M., Schaal, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Stawarz, Lukasz, Strong, A. W., Suson, D. J., Tahara, M., Takahashi, H., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vianello, G., Werner, M., Winer, B. L., Wood, K. S., Wood, M., and Zaharijas, G.
Abstract: The Fermi bubbles are two large structures in the gamma-ray sky extending to 55 degrees above and below the Galactic center. We analyze 50 months of Fermi Large Area Telescope data between 100MeV and 500 GeV above 10 degrees in Galactic latitude to derive the spectrum and morphology of the Fermi bubbles. We thoroughly explore the systematic uncertainties that arise when modeling the Galactic diffuse emission through two separate approaches. The gamma-ray spectrum is well described by either a log parabola or a power law with an exponential cutoff. We exclude a simple power law with more than 7 sigma significance. The power law with an exponential cutoff has an index of 1.9 +/- 0.2 and a cutoff energy of 110 +/- 50 GeV. We find that the gamma-ray luminosity of the bubbles is 4.4(-0.9)(+2.4) x 10(37) erg s(-1). We confirm a significant enhancement of gamma-ray emission in the southeastern part of the bubbles, but we do not find significant evidence for a jet. No significant variation of the spectrum across the bubbles is detected. The width of the boundary of the bubbles is estimated to be 3.4(-2.6)(+3.7) deg. Both inverse Compton (IC) models and hadronic models including IC emission from secondary leptons fit the gamma-ray data well. In the IC scenario, synchrotron emission from the same population of electrons can also explain the WMAP and Planck microwave haze with a magnetic field between 5 and 20 mu G., AuthorCount:135
Published: 2014
Full Text: View/download PDF

38. SEARCH FOR COSMIC-RAY-INDUCED GAMMA-RAY EMISSION IN GALAXY CLUSTERS

Author: Ackermann, M., Ajello, M., Albert, A., Allafort, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Chaves, R. C. G., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hewitt, J., Hughes, R. E., Jeltema, T. E., Johannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Garde, Maja Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ruan, J., Sanchez-Conde, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Storm, E., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Zimmer, Stephan, Pinzke, A., Pfrommer, C., Ackermann, M., Ajello, M., Albert, A., Allafort, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Chaves, R. C. G., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Digel, S. W., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Gustafsson, M., Hadasch, D., Hayashida, M., Hewitt, J., Hughes, R. E., Jeltema, T. E., Johannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Garde, Maja Llena, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ruan, J., Sanchez-Conde, M., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Storm, E., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Zimmer, Stephan, Pinzke, A., and Pfrommer, C.
Abstract: Current theories predict relativistic hadronic particle populations in clusters of galaxies in addition to the already observed relativistic leptons. In these scenarios hadronic interactions give rise to neutral pions which decay into gamma rays that are potentially observable with the Large Area Telescope (LAT) on board the Fermi space telescope. We present a joint likelihood analysis searching for spatially extended gamma-ray emission at the locations of 50 galaxy clusters in four years of Fermi-LAT data under the assumption of the universal cosmic-ray (CR) model proposed by Pinzke & Pfrommer. We find an excess at a significance of 2.7 sigma, which upon closer inspection, however, is correlated to individual excess emission toward three galaxy clusters: A400, A1367, and A3112. We discuss these cases in detail and conservatively attribute the emission to unmodeled background systems (for example, radio galaxies within the clusters). Through the combined analysis of 50 clusters, we exclude hadronic injection efficiencies in simple hadronic models above 21% and establish limits on the CR to thermal pressure ratio within the virial radius, R-200, to be below 1.25%-1.4% depending on the morphological classification. In addition, we derive new limits on the gamma-ray flux from individual clusters in our sample., AuthorCount:126
Published: 2014
Full Text: View/download PDF

39. HIGH-ENERGY GAMMA-RAY EMISSION FROM SOLAR FLARES : SUMMARY OF FERMI LARGE AREA TELESCOPE DETECTIONS AND ANALYSIS OF TWO M-CLASS FLARES

Author: Ackermann, M., Ajello, M., Albert, A., Allafort, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bonamente, E., Bottacini, E., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chen, Q., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, W. N., Kamae, T., Kawano, T., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Murphy, R., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Takeuchi, Y., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, D. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Ackermann, M., Ajello, M., Albert, A., Allafort, A., Baldini, L., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bissaldi, E., Bonamente, E., Bottacini, E., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chen, Q., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, W. N., Kamae, T., Kawano, T., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Murphy, R., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Petrosian, V., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Ritz, S., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Takeuchi, Y., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, D. L., Wood, K. S., Wood, M., and Yang, Zhaoyu
Abstract: We present the detections of 18 solar flares detected in high-energy gamma-rays (above 100 MeV) with the Fermi Large Area Telescope (LAT) during its first 4 yr of operation. This work suggests that particle acceleration up to very high energies in solar flares is more common than previously thought, occurring even in modest flares, and for longer durations. Interestingly, all these flares are associated with fairly fast coronal mass ejections (CMEs). We then describe the detailed temporal, spatial, and spectral characteristics of the first two long-lasting events: the 2011 March 7 flare, a moderate (M3.7) impulsive flare followed by slowly varying gamma-ray emission over 13 hr, and the 2011 June 7 M2.5 flare, which was followed by gamma-ray emission lasting for 2 hr. We compare the Fermi LAT data with X-ray and proton data measurements from GOES and RHESSI. We argue that the gamma-rays are more likely produced through pion decay than electron bremsstrahlung, and we find that the energy spectrum of the proton distribution softens during the extended emission of the 2011 March 7 flare. This would disfavor a trapping scenario for particles accelerated during the impulsive phase of the flare and point to a continuous acceleration process at play for the duration of the flares. CME shocks are known for accelerating the solar energetic particles (SEPs) observed in situ on similar timescales, but it might be challenging to explain the production of gamma-rays at the surface of the Sun while the CME is halfway to the Earth. A stochastic turbulence acceleration process occurring in the solar corona is another likely scenario. Detailed comparison of characteristics of SEPs and gamma-ray-emitting particles for several flares will be helpful to distinguish between these two possibilities., AuthorCount:147
Published: 2014
Full Text: View/download PDF

40. The First Pulse of the Extremely Bright GRB 130427A : A Test Lab for Synchrotron Shocks

Author: Preece, R., Burgess, J. Michael, von Kienlin, A., Bhat, P. N., Briggs, M. S., Byrne, D., Chaplin, V., Cleveland, W., Collazzi, A. C., Connaughton, V., Diekmann, A., Fitzpatrick, G., Foley, S., Gibby, M., Giles, M., Goldstein, A., Greiner, J., Gruber, D., Jenke, P., Kippen, R. M., Kouveliotou, C., McBreen, S., Meegan, C., Paciesas, W. S., Pelassa, V., Tierney, D., van der Horst, A. J., Wilson-Hodge, C., Xiong, S., Younes, G., Yu, H. -F, Ackermann, M., Ajello, M., Axelsson, Magnus, Baldini, L., Barbiellini, G., Baring, M. G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Granot, J., Grenier, I. A., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Iyyani, Shabnam, Jogler, T., Joannesson, G., Kawano, T., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Ryde, F., Sartori, A., Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Zhu, S., Preece, R., Burgess, J. Michael, von Kienlin, A., Bhat, P. N., Briggs, M. S., Byrne, D., Chaplin, V., Cleveland, W., Collazzi, A. C., Connaughton, V., Diekmann, A., Fitzpatrick, G., Foley, S., Gibby, M., Giles, M., Goldstein, A., Greiner, J., Gruber, D., Jenke, P., Kippen, R. M., Kouveliotou, C., McBreen, S., Meegan, C., Paciesas, W. S., Pelassa, V., Tierney, D., van der Horst, A. J., Wilson-Hodge, C., Xiong, S., Younes, G., Yu, H. -F, Ackermann, M., Ajello, M., Axelsson, Magnus, Baldini, L., Barbiellini, G., Baring, M. G., Bastieri, D., Bellazzini, R., Bissaldi, E., Bonamente, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Godfrey, G., Granot, J., Grenier, I. A., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Iyyani, Shabnam, Jogler, T., Joannesson, G., Kawano, T., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., Michelson, P. F., Mizuno, T., Monzani, M. E., Moretti, E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Roth, M., Ryde, F., Sartori, A., Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., and Zhu, S.
Abstract: Gamma-ray burst (GRB) 130427A is one of the most energetic GRBs ever observed. The initial pulse up to 2.5 seconds is possibly the brightest well-isolated pulse observed to date. A fine time resolution spectral analysis shows power-law decays of the peak energy from the onset of the pulse, consistent with models of internal synchrotron shock pulses. However, a strongly correlated power-law behavior is observed between the luminosity and the spectral peak energy that is inconsistent with curvature effects arising in the relativistic outflow. It is difficult for any of the existing models to account for all of the observed spectral and temporal behaviors simultaneously., AuthorCount:159
Published: 2014
Full Text: View/download PDF

41. THE FIRST FERMI-LAT GAMMA-RAY BURST CATALOG

Author: Ackermann, M., Ajello, M., Asano, K., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bhat, P. N., Bissaldi, E., Bloom, E. D., Bonamente, E., Bonnell, J., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgess, J. Michael, Buson, S., Byrne, D., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Connaughton, V., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Dingus, B. L., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Ferrara, E. C., Fitzpatrick, G., Foley, S., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Goldstein, A., Granot, J., Grenier, I. A., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hanabata, Y., Hayashida, M., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Kippen, R. M., Knoedlseder, J., Kocevski, D., Kouveliotou, C., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lee, S. -H, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Massaro, F., Mayer, M., Mazziotta, M. N., McBreen, S., McEnery, J. E., McGlynn, S., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paciesas, W. S., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Preece, R., Racusin, J. L., Raino, S., Rando, R., Rau, A., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romoli, C., Roth, M., Ryde, F., Parkinson, P. M. Saz, Schalk, T. L., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Takeuchi, Y., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tierney, D., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., van der Horst, A. J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Winer, B. L., Wood, K. S., Wood, M., Xiong, S., Yang, Zhaoyu, Ackermann, M., Ajello, M., Asano, K., Axelsson, Magnus, Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bhat, P. N., Bissaldi, E., Bloom, E. D., Bonamente, E., Bonnell, J., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgess, J. Michael, Buson, S., Byrne, D., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Connaughton, V., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Dingus, B. L., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Ferrara, E. C., Fitzpatrick, G., Foley, S., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Goldstein, A., Granot, J., Grenier, I. A., Grove, J. E., Gruber, D., Guiriec, S., Hadasch, D., Hanabata, Y., Hayashida, M., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Kippen, R. M., Knoedlseder, J., Kocevski, D., Kouveliotou, C., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lee, S. -H, Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Massaro, F., Mayer, M., Mazziotta, M. N., McBreen, S., McEnery, J. E., McGlynn, S., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paciesas, W. S., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Preece, R., Racusin, J. L., Raino, S., Rando, R., Rau, A., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romoli, C., Roth, M., Ryde, F., Parkinson, P. M. Saz, Schalk, T. L., Sgro, C., Siskind, E. J., Sonbas, E., Spandre, G., Spinelli, P., Suson, D. J., Tajima, H., Takahashi, H., Takeuchi, Y., Tanaka, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tierney, D., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., van der Horst, A. J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Winer, B. L., Wood, K. S., Wood, M., Xiong, S., and Yang, Zhaoyu
Abstract: In three years of observations since the beginning of nominal science operations in 2008 August, the Large Area Telescope (LAT) on board the Fermi Gamma-Ray Space Telescope has observed high-energy (greater than or similar to 20 MeV) gamma-ray emission from 35 gamma-ray bursts (GRBs). Among these, 28 GRBs have been detected above 100 MeV and 7 GRBs above similar to 20 MeV. The first Fermi-LAT catalog of GRBs is a compilation of these detections and provides a systematic study of high-energy emission from GRBs for the first time. To generate the catalog, we examined 733 GRBs detected by the Gamma-Ray Burst Monitor (GBM) on Fermi and processed each of them using the same analysis sequence. Details of the methodology followed by the LAT collaboration for the GRB analysis are provided. We summarize the temporal and spectral properties of the LAT-detected GRBs. We also discuss characteristics of LAT-detected emission such as its delayed onset and longer duration compared with emission detected by the GBM, its power-law temporal decay at late times, and the fact that it is dominated by a power-law spectral component that appears in addition to the usual Band model., AuthorCount:180
Published: 2013
Full Text: View/download PDF

42. THE SECOND FERMI LARGE AREA TELESCOPE CATALOG OF GAMMA-RAY PULSARS

Author: Abdo, A. A., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Belfiore, A., Bellazzini, R., Bhattacharyya, B., Bissaldi, E., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgay, M., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Camilo, F., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, Oe ., Charles, E., Chaty, S., Chaves, R. C. G., Chekhtman, A., Chen, A. W., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cognard, I., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., De Angelis, A., DeCesar, M. E., De Luca, A., Den Hartog, P. R., De Palma, F., Dermer, C. D., Desvignes, G., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Espinoza, C. M., Falletti, L., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Freire, P. C. C., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gotthelf, E. V., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hessels, J., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Janssen, G. H., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Johnson, T. J., Johnson, W. N., Johnston, S., Kamae, T., Kataoka, J., Keith, M., Kerr, M., Knoedlseder, J., Kramer, M., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Lyne, A. G., Manchester, R. N., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., McLaughlin, M. A., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Pletsch, H. J., Porter, T. A., Possenti, A., Raino, S., Rando, R., Ransom, S. M., Ray, P. S., Razzano, M., Rea, N., Reimer, A., Reimer, O., Renault, N., Reposeur, T., Ritz, S., Romani, R. W., Roth, M., Rousseau, R., Roy, J., Ruan, J., Sartori, A., Parkinson, P. M. Saz, Scargle, J. D., Schulz, A., Sgro, C., Shannon, R., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stappers, B. W., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Theureau, G., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Venter, C., Vianello, G., Vitale, V., Wang, N., Weltevrede, P., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Abdo, A. A., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Belfiore, A., Bellazzini, R., Bhattacharyya, B., Bissaldi, E., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burgay, M., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Camilo, F., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, Oe ., Charles, E., Chaty, S., Chaves, R. C. G., Chekhtman, A., Chen, A. W., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cognard, I., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., De Angelis, A., DeCesar, M. E., De Luca, A., Den Hartog, P. R., De Palma, F., Dermer, C. D., Desvignes, G., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Dubois, R., Dumora, D., Espinoza, C. M., Falletti, L., Favuzzi, C., Ferrara, E. C., Focke, W. B., Franckowiak, A., Freire, P. C. C., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gotthelf, E. V., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hessels, J., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Janssen, G. H., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Johnson, T. J., Johnson, W. N., Johnston, S., Kamae, T., Kataoka, J., Keith, M., Kerr, M., Knoedlseder, J., Kramer, M., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Lyne, A. G., Manchester, R. N., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., McLaughlin, M. A., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Parent, D., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Pletsch, H. J., Porter, T. A., Possenti, A., Raino, S., Rando, R., Ransom, S. M., Ray, P. S., Razzano, M., Rea, N., Reimer, A., Reimer, O., Renault, N., Reposeur, T., Ritz, S., Romani, R. W., Roth, M., Rousseau, R., Roy, J., Ruan, J., Sartori, A., Parkinson, P. M. Saz, Scargle, J. D., Schulz, A., Sgro, C., Shannon, R., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stappers, B. W., Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Theureau, G., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Venter, C., Vianello, G., Vitale, V., Wang, N., Weltevrede, P., Winer, B. L., Wolff, M. T., Wood, D. L., Wood, K. S., Wood, M., and Yang, Zhaoyu
Abstract: This catalog summarizes 117 high-confidence >= 0.1 GeV gamma-ray pulsar detections using three years of data acquired by the Large Area Telescope (LAT) on the Fermi satellite. Half are neutron stars discovered using LAT data through periodicity searches in gamma-ray and radio data around LAT unassociated source positions. The 117 pulsars are evenly divided into three groups: millisecond pulsars, young radio-loud pulsars, and young radio-quiet pulsars. We characterize the pulse profiles and energy spectra and derive luminosities when distance information exists. Spectral analysis of the off-peak phase intervals indicates probable pulsar wind nebula emission for four pulsars, and off-peak magnetospheric emission for several young and millisecond pulsars. We compare the gamma-ray properties with those in the radio, optical, and X-ray bands. We provide flux limits for pulsars with no observed gamma-ray emission, highlighting a small number of gamma-faint, radio-loud pulsars. The large, varied gamma-ray pulsar sample constrains emission models. Fermi's selection biases complement those of radio surveys, enhancing comparisons with predicted population distributions., AuthorCount:211
Published: 2013
Full Text: View/download PDF

43. CONSTRAINTS ON THE GALACTIC POPULATION OF TeV PULSAR WIND NEBULAE USING FERMI LARGE AREA TELESCOPE OBSERVATIONS

Author: Acero, F., Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Palma, F., Dermer, C. D., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gregoire, T., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., SUBJackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Roth, M., Rousseau, R., Parkinson, P. M. Saz, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Acero, F., Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Palma, F., Dermer, C. D., Di Venere, L., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Gregoire, T., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., SUBJackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kawano, T., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Marelli, M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Roth, M., Rousseau, R., Parkinson, P. M. Saz, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., and Yang, Zhaoyu
Abstract: Pulsar wind nebulae (PWNe) have been established as the most populous class of TeV gamma-ray emitters. Since launch, the Fermi Large Area Telescope (LAT) has identified five high-energy (100 MeV < E < 100 GeV) gamma-ray sources as PWNe and detected a large number of PWN candidates, all powered by young and energetic pulsars. The wealth of multi-wavelength data available and the new results provided by Fermi-LAT give us an opportunity to find new PWNe and to explore the radiative processes taking place in known ones. The TeV gamma-ray unidentified (UNID) sources are the best candidates for finding new PWNe. Using 45 months of Fermi-LAT data for energies above 10 GeV, an analysis was performed near the position of 58 TeV PWNe and UNIDs within 5. of the Galactic plane to establish new constraints on PWN properties and find new clues on the nature of UNIDs. Of the 58 sources, 30 were detected, and this work provides their gamma-ray fluxes for energies above 10 GeV. The spectral energy distributions and upper limits, in the multi-wavelength context, also provide new information on the source nature and can help distinguish between emission scenarios, i.e., between classification as a pulsar candidate or as a PWN candidate. Six new GeV PWN candidates are described in detail and compared with existing models. A population study of GeV PWN candidates as a function of the pulsar/PWN system characteristics is presented., AuthorCount:158
Published: 2013
Full Text: View/download PDF

44. DETERMINATION OF THE POINT-SPREAD FUNCTION FOR THE FERMI LARGE AREA TELESCOPE FROM ON-ORBIT DATA AND LIMITS ON PAIR HALOS OF ACTIVE GALACTIC NUCLEI

Author: Ackermann, M., Ajello, M., Allafort, A., Asano, K., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chaty, S., Chekhtman, A., Cheung, C. C., Chiang, J., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Colafrancesco, S., Conrad, Jan, Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grandi, P., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Kamae, T., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lavalley, C., Lee, S. -H, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McConville, W., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nemmen, R., Nishino, S., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reyes, L. C., Ritz, S., Rochester, L. S., Romoli, C., Roth, M., Sanchez, D. A., Parkinson, P. M. Saz, Scargle, J. D., Sgro, C., Siskind, E. J., Snyder, A., Spandre, G., Spinelli, P., Stephens, T. E., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Waite, A. P., Wallace, E., Weltevrede, P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Zimmer, Stephan, Ackermann, M., Ajello, M., Allafort, A., Asano, K., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Charles, E., Chaty, S., Chekhtman, A., Cheung, C. C., Chiang, J., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Colafrancesco, S., Conrad, Jan, Cutini, S., D'Ammando, F., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, S., Drlica-Wagner, A., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grandi, P., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hou, X., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, R. P., Johnson, A. S., Kamae, T., Kataoka, J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lavalley, C., Lee, S. -H, Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McConville, W., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Nemmen, R., Nishino, S., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Pelassa, V., Perkins, J. S., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Poon, H., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Reyes, L. C., Ritz, S., Rochester, L. S., Romoli, C., Roth, M., Sanchez, D. A., Parkinson, P. M. Saz, Scargle, J. D., Sgro, C., Siskind, E. J., Snyder, A., Spandre, G., Spinelli, P., Stephens, T. E., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tibolla, O., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., von Kienlin, A., Waite, A. P., Wallace, E., Weltevrede, P., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: The Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope is a pair-conversion telescope designed to detect photons with energies from approximate to 20 MeV to > 300 GeV. The pre-launch response functions of the LAT were determined through extensive Monte Carlo simulations and beam tests. The point-spread function (PSF) characterizing the angular distribution of reconstructed photons as a function of energy and geometry in the detector is determined here from two years of on-orbit data by examining the distributions of gamma rays from pulsars and active galactic nuclei (AGNs). Above 3 GeV, the PSF is found to be broader than the pre-launch PSF. We checked for dependence of the PSF on the class of gamma-ray source and observation epoch and found none. We also investigated several possible spatial models for pair-halo emission around BL Lac AGNs. We found no evidence for a component with spatial extension larger than the PSF and set upper limits on the amplitude of halo emission in stacked images of low-and high-redshift BL Lac AGNs and the TeV blazars 1ES0229 + 200 and 1ES0347-121., AuthorCount:174
Published: 2013
Full Text: View/download PDF

45. Detection of the Characteristic Pion-Decay Signature in Supernova Remnants

Author: Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, O., Charles, E., Chaty, S., Chaves, R. C. G., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Corbel, S., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J. W., Hill, A. B., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Katsuta, J., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Romoli, C., Sanchez-Conde, M., Schulz, A., Sgro, C., Simeon, P. E., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stecker, F. W., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Tibolla, O., Tinivella, M., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Yamazaki, R., Yang, Zhaoyu, Zimmer, Stephan, Ackermann, M., Ajello, M., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Borgland, A. W., Bottacini, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Busetto, G., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cecchi, C., Celik, O., Charles, E., Chaty, S., Chaves, R. C. G., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Cillis, A. N., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Corbel, S., Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Falletti, L., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. -H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J. W., Hill, A. B., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Kamae, T., Kataoka, J., Katsuta, J., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Madejski, G. M., Massaro, F., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mignani, R. P., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Nemmen, R., Nuss, E., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Ritz, S., Romoli, C., Sanchez-Conde, M., Schulz, A., Sgro, C., Simeon, P. E., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stecker, F. W., Strong, A. W., Suson, D. J., Tajima, H., Takahashi, H., Takahashi, T., Tanaka, T., Thayer, J. G., Thayer, J. B., Thompson, D. J., Thorsett, S. E., Tibaldo, L., Tibolla, O., Tinivella, M., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Yamazaki, R., Yang, Zhaoyu, and Zimmer, Stephan
Abstract: Cosmic rays are particles (mostly protons) accelerated to relativistic speeds. Despite wide agreement that supernova remnants (SNRs) are the sources of galactic cosmic rays, unequivocal evidence for the acceleration of protons in these objects is still lacking. When accelerated protons encounter interstellar material, they produce neutral pions, which in turn decay into gamma rays. This offers a compelling way to detect the acceleration sites of protons. The identification of pion-decay gamma rays has been difficult because high-energy electrons also produce gamma rays via bremsstrahlung and inverse Compton scattering. We detected the characteristic pion-decay feature in the gamma-ray spectra of two SNRs, IC 443 and W44, with the Fermi Large Area Telescope. This detection provides direct evidence that cosmic-ray protons are accelerated in SNRs., AuthorCount:169
Published: 2013
Full Text: View/download PDF

46. THE FIRST FERMI-LAT CATALOG OF SOURCES ABOVE 10 GeV

Author: Ackermann, M., Ajello, M., Allafort, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Belfiore, A., Bellazzini, R., Bernieri, E., Bissaldi, E., Bloom, E. D., Bonamente, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Campana, R., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., De Angelis, A., De Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hughes, R. E., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Knodlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Massaro, E., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Ormes, J. F., Paneque, David, Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romani, R. W., Roth, M., Parkinson, P. M. Saz, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stawarz, Lukasz, Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Wood, M., Ackermann, M., Ajello, M., Allafort, A., Atwood, W. B., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Belfiore, A., Bellazzini, R., Bernieri, E., Bissaldi, E., Bloom, E. D., Bonamente, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Burnett, T. H., Buson, S., Caliandro, G. A., Cameron, R. A., Campana, R., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., D'Ammando, F., De Angelis, A., De Palma, F., Dermer, C. D., Desiante, R., Digel, S. W., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Fortin, P., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giglietto, N., Giommi, P., Giordano, F., Giroletti, M., Godfrey, G., Gomez-Vargas, G. A., Grenier, I. A., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hughes, R. E., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Knodlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Massaro, E., Mayer, M., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Ormes, J. F., Paneque, David, Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Razzano, M., Reimer, A., Reimer, O., Reposeur, T., Ritz, S., Romani, R. W., Roth, M., Parkinson, P. M. Saz, Schulz, A., Sgro, C., Siskind, E. J., Smith, D. A., Spandre, G., Spinelli, P., Stawarz, Lukasz, Strong, A. W., Suson, D. J., Takahashi, H., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., and Wood, M.
Abstract: We present a catalog of gamma-ray sources at energies above 10 GeV based on data from the Large Area Telescope (LAT) accumulated during the first 3 yr of the Fermi Gamma-ray Space Telescope mission. The first Fermi catalog of > 10 GeV sources (1FHL) has 514 sources. For each source we present location, spectrum, a measure of variability, and associations with cataloged sources at other wavelengths. We found that 449 (87%) could be associated with known sources, of which 393 (76% of the 1FHL sources) are active galactic nuclei. Of the 27 sources associated with known pulsars, we find 20 (12) to have significant pulsations in the range > 10 GeV (> 25 GeV). In this work we also report that, at energies above 10 GeV, unresolved sources account for 27% +/- 8% of the isotropic. gamma-ray background, while the unresolved Galactic population contributes only at the few percent level to the Galactic diffuse background. We also highlight the subset of the 1FHL sources that are best candidates for detection at energies above 50-100 GeV with current and future ground-based gamma-ray observatories., AuthorCount:159
Published: 2013
Full Text: View/download PDF

47. THE FERMI ALL-SKY VARIABILITY ANALYSIS : A LIST OF FLARING GAMMA-RAY SOURCES AND THE SEARCH FOR TRANSIENTS IN OUR GALAXY

Author: Ackermann, M., Ajello, M., Albert, A., Allafort, A., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M-H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Romoli, C., Roth, M., Sanchez-Conde, M., Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Wood, M., Yang, Zhaoyu, Ackermann, M., Ajello, M., Albert, A., Allafort, A., Antolini, E., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Blandford, R. D., Bloom, E. D., Bonamente, E., Bottacini, E., Bouvier, A., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cavazzuti, E., Cecchi, C., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., Di Venere, L., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M-H, Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Hughes, R. E., Inoue, Y., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, W. N., Kamae, T., Kataoka, J., Kawano, T., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Panetta, J. H., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Romoli, C., Roth, M., Sanchez-Conde, M., Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Suson, D. J., Takahashi, H., Takeuchi, Y., Thayer, J. G., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Tronconi, V., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Wood, M., and Yang, Zhaoyu
Abstract: In this paper, we present the Fermi All-sky Variability Analysis (FAVA), a tool to systematically study the variability of the gamma-ray sky measured by the Large Area Telescope on board the Fermi Gamma-ray Space Telescope. For each direction on the sky, FAVA compares the number of gamma-rays observed in a given time window to the number of gamma-rays expected for the average emission detected from that direction. This method is used in weekly time intervals to derive a list of 215 flaring gamma-ray sources. We proceed to discuss the 27 sources found at Galactic latitudes smaller than 10 degrees and show that, despite their low latitudes, most of them are likely of extragalactic origin., AuthorCount:155
Published: 2013
Full Text: View/download PDF

48. ASSOCIATING LONG-TERM gamma-RAY VARIABILITY WITH THE SUPERORBITAL PERIOD OF LS I+61 degrees 303

Author: Ackermann, M., Ajello, M., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bonamente, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Angelis, A., Den Hartog, P. R., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., Drell, P. S., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hill, A. B., Horan, D., Hughes, R. E., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, T. J., Kawano, T., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Papitto, A., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Rea, N., Reimer, A., Reimer, O., Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. G., Thayer, J. B., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., Wood, K. S., Ackermann, M., Ajello, M., Ballet, J., Barbiellini, G., Bastieri, D., Bellazzini, R., Bonamente, E., Brandt, T. J., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., Cohen-Tanugi, J., Cominsky, L. R., Conrad, Jan, Cutini, S., Dalton, M., D'Ammando, F., de Angelis, A., Den Hartog, P. R., de Palma, F., Dermer, C. D., Digel, S. W., Di Venere, L., Drell, P. S., Dubois, R., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Franckowiak, A., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Germani, S., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hill, A. B., Horan, D., Hughes, R. E., Jogler, T., Johannesson, G., Johnson, A. S., Johnson, T. J., Kawano, T., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Li, J., Longo, F., Lovellette, M. N., Lubrano, P., Mayer, M., Mazziotta, M. N., McEnery, J. E., Michelson, P. F., Mizuno, T., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Okumura, A., Orienti, M., Orlando, E., Ormes, J. F., Paneque, D., Papitto, A., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Raino, S., Rando, R., Razzano, M., Rea, N., Reimer, A., Reimer, O., Scargle, J. D., Schulz, A., Sgro, C., Siskind, E. J., Spandre, G., Spinelli, P., Takahashi, H., Thayer, J. G., Thayer, J. B., Tinivella, M., Torres, D. F., Tosti, G., Troja, E., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Werner, M., Winer, B. L., and Wood, K. S.
Abstract: Gamma-ray binaries are stellar systems for which the spectral energy distribution (discounting the thermal stellar emission) peaks at high energies. Detected from radio to TeV gamma rays, the gamma-ray binary LS I + 61 degrees 303 is highly variable across all frequencies. One aspect of this system's variability is the modulation of its emission with the timescale set by the similar to 26.4960 day orbital period. Here we show that, during the time of our observations, the gamma-ray emission of LS I + 61 degrees 303 also presents a sinusoidal variability consistent with the previously known superorbital period of 1667 days. This modulation is more prominently seen at orbital phases around apastron, whereas it does not introduce a visible change close to periastron. It is also found in the appearance and disappearance of variability at the orbital period in the power spectrum of the data. This behavior could be explained by a quasi-cyclical evolution of the equatorial outflow of the Be companion star, whose features influence the conditions for generating gamma rays. These findings open the possibility to use gamma-ray observations to study the outflows of massive stars in eccentric binary systems., AuthorCount:129
Published: 2013
Full Text: View/download PDF

49. PSR J2021+4026 IN THE GAMMA CYGNI REGION : THE FIRST VARIABLE gamma-RAY PULSAR SEEN BY THE Fermi LAT

Author: Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bellazzini, R., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., D'Ammando, F., de Palma, F., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Jogler, T., Johnson, A. S., Johnson, T. J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lubrano, P., Malyshev, D., Marelli, M., Mayer, M., Mazziotta, M. N., Mehault, J., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Ray, P. S., Razzano, M., Reimer, O., Reposeur, T., Romani, R. W., Sartori, A., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Smith, D. A., Spinelli, P., Strong, A. W., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Venter, C., Vianello, G., Vitale, V., Winer, B. L., Wood, K. S., Allafort, A., Baldini, L., Ballet, J., Barbiellini, G., Baring, M. G., Bastieri, D., Bellazzini, R., Bonamente, E., Bottacini, E., Brandt, T. J., Bregeon, J., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Chaves, R. C. G., Chekhtman, A., Chiang, J., Chiaro, G., Ciprini, S., Claus, R., D'Ammando, F., de Palma, F., Digel, S. W., Di Venere, L., Drell, P. S., Favuzzi, C., Ferrara, E. C., Franckowiak, A., Fusco, P., Gargano, F., Gasparrini, D., Giglietto, N., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Guiriec, S., Hadasch, D., Harding, A. K., Hayashida, M., Hayashi, K., Hays, E., Hewitt, J., Hill, A. B., Horan, D., Hou, X., Jogler, T., Johnson, A. S., Johnson, T. J., Kerr, M., Knoedlseder, J., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lubrano, P., Malyshev, D., Marelli, M., Mayer, M., Mazziotta, M. N., Mehault, J., Mizuno, T., Monzani, M. E., Morselli, A., Murgia, S., Nemmen, R., Nuss, E., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Pesce-Rollins, M., Pierbattista, M., Piron, F., Pivato, G., Porter, T. A., Raino, S., Rando, R., Ray, P. S., Razzano, M., Reimer, O., Reposeur, T., Romani, R. W., Sartori, A., Parkinson, P. M. Saz, Sgro, C., Siskind, E. J., Smith, D. A., Spinelli, P., Strong, A. W., Takahashi, H., Thayer, J. B., Thompson, D. J., Tibaldo, L., Tinivella, M., Torres, D. F., Tosti, G., Uchiyama, Y., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Venter, C., Vianello, G., Vitale, V., Winer, B. L., and Wood, K. S.
Abstract: Long-term monitoring of PSR J2021+4026 in the heart of the Cygnus region with the Fermi Large Area Telescope unveiled a sudden decrease in flux above 100 MeV over a timescale shorter than a week. The jump was near MJD 55850 (2011 October 16), with the flux decreasing from (8.33+/-0.08) x 10(-10) erg cm(-2) s(-1) to (6.86+/-0.13) x 10(-10) erg cm(-2) s(-1). Simultaneously, the frequency spindown rate increased from (7.8 +/- 0.1) x 10(-13) Hz s(-1) to (8.1 +/- 0.1) x 10(-13) Hz s(-1). Significant (>5 sigma) changes in the pulse profile and marginal (<3 sigma) changes in the emission spectrum occurred at the same time. There is also evidence for a small, steady flux increase over the 3 yr preceding MJD 55850. This is the first observation at gamma-ray energies of mode changes and intermittent behavior, observed at radio wavelengths for other pulsars. We argue that the change in pulsed gamma-ray emission is due to a change in emission beaming and we speculate that it is precipitated by a shift in the magnetic field structure, leading to a change of either effective magnetic inclination or effective current., AuthorCount:114;Funding agencies:NASA in the United States; DOE in the United States; CEA/Irfu in France; IN2P3/CNRS in France: ASI in Italy; INFN in Italy; MEXT in Japan; KEK in Japan; JAXA in Japan; K.A. Wallenberg Foundation in Sweden; Swedish Research Council in Sweden; National Space Board in Sweden; INAF in Italy; CNES in France
Published: 2013
Full Text: View/download PDF

50. MULTIWAVELENGTH OBSERVATIONS OF GRB 110731A : GeV EMISSION FROM ONSET TO AFTERGLOW

Author: Ackermann, M., Ajello, M., Asano, K., Baldini, L., Barbiellini, G., Baring, M. G., Bastieri, D., Bellazzini, R., Blandford, R. D., Bonamente, E., Borgland, A. W., Bottacini, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Granot, J., Greiner, J., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Hayashida, M., Hays, E., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Mehault, J., Meszaros, P., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romoli, C., Roth, M., Ryde, F., Sanchez, D. A., Sgro, C., Siskind, E. J., Sonbas, E., Spinelli, P., Stamatikos, M., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Gruber, D., Bhat, P. N., Bissaldi, E., Briggs, M. S., Burgess, J. M., Connaughton, V., Foley, S., Kippen, R. M., Kouveliotou, C., McBreen, S., McGlynn, S., Paciesas, W. S., Pelassa, V., Preece, R., Rau, A., van der Horst, A. J., von Kienlin, A., Kann, D. A., Filgas, R., Klose, S., Kruhler, T., Fukui, A., Sako, T., Tristram, P. J., Oates, S. R., Ukwatta, T. N., Littlejohns, O., Ackermann, M., Ajello, M., Asano, K., Baldini, L., Barbiellini, G., Baring, M. G., Bastieri, D., Bellazzini, R., Blandford, R. D., Bonamente, E., Borgland, A. W., Bottacini, E., Bregeon, J., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Cecchi, C., Charles, E., Chaves, R. C. G., Chekhtman, A., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, Jan, Cutini, S., D'Ammando, F., de Angelis, A., de Palma, F., Dermer, C. D., do Couto e Silva, E., Drell, P. S., Drlica-Wagner, A., Favuzzi, C., Fegan, S. J., Focke, W. B., Franckowiak, A., Fukazawa, Y., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Granot, J., Greiner, J., Grenier, I. A., Grove, J. E., Guiriec, S., Hadasch, D., Hanabata, Y., Hayashida, M., Hays, E., Hughes, R. E., Jackson, M. S., Jogler, T., Johannesson, G., Johnson, A. S., Knoedlseder, J., Kocevski, D., Kuss, M., Lande, J., Larsson, Stefan, Latronico, L., Longo, F., Loparco, F., Lovellette, M. N., Lubrano, P., Mazziotta, M. N., McEnery, J. E., Mehault, J., Meszaros, P., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Monte, C., Monzani, M. E., Moretti, E., Morselli, A., Moskalenko, I. V., Murgia, S., Naumann-Godo, M., Norris, J. P., Nuss, E., Nymark, T., Ohno, M., Ohsugi, T., Omodei, N., Orienti, M., Orlando, E., Paneque, D., Perkins, J. S., Pesce-Rollins, M., Piron, F., Pivato, G., Racusin, J. L., Raino, S., Rando, R., Razzano, M., Razzaque, S., Reimer, A., Reimer, O., Romoli, C., Roth, M., Ryde, F., Sanchez, D. A., Sgro, C., Siskind, E. J., Sonbas, E., Spinelli, P., Stamatikos, M., Takahashi, H., Tanaka, T., Thayer, J. G., Thayer, J. B., Tibaldo, L., Tinivella, M., Tosti, G., Troja, E., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vianello, G., Vitale, V., Waite, A. P., Winer, B. L., Wood, K. S., Yang, Zhaoyu, Gruber, D., Bhat, P. N., Bissaldi, E., Briggs, M. S., Burgess, J. M., Connaughton, V., Foley, S., Kippen, R. M., Kouveliotou, C., McBreen, S., McGlynn, S., Paciesas, W. S., Pelassa, V., Preece, R., Rau, A., van der Horst, A. J., von Kienlin, A., Kann, D. A., Filgas, R., Klose, S., Kruhler, T., Fukui, A., Sako, T., Tristram, P. J., Oates, S. R., Ukwatta, T. N., and Littlejohns, O.
Abstract: We report on the multiwavelength observations of the bright, long gamma-ray burst GRB 110731A, by the Fermi and Swift observatories, and by the MOA and GROND optical telescopes. The analysis of the prompt phase reveals that GRB 110731A shares many features with bright Large Area Telescope bursts observed by Fermi during the first three years on-orbit: a light curve with short time variability across the whole energy range during the prompt phase, delayed onset of the emission above 100 MeV, extra power-law component and temporally extended high-energy emission. In addition, this is the first GRB for which simultaneous GeV, X-ray, and optical data are available over multiple epochs beginning just after the trigger time and extending for more than 800 s, allowing temporal and spectral analysis in different epochs that favor emission from the forward shock in a wind-type medium. The observed temporally extended GeV emission is most likely part of the high-energy end of the afterglow emission. Both the single-zone pair transparency constraint for the prompt signal and the spectral and temporal analysis of the forward-shock afterglow emission independently lead to an estimate of the bulk Lorentz factor of the jet Gamma similar to 500-550.
Published: 2013
Full Text: View/download PDF

Catalog

Books, media, physical & digital resources

See catalog results

Searchworks

Select search scope, currently: Articles Catalog books, media & more in Jio Institute collections Articles journal articles & other e-resources

Search

Search Constraints

Refine your results

Search Limiters

Publication Year Range

Publication Type

Database

Publisher

73 results on '"PESCE-ROLLINS, M."'

Search Results

Catalog

Select search scope, currently: Articles

Catalog

books, media & more in Jio Institute collections

Articles

journal articles & other e-resources