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1. Characterization of a tagged gamma-ray beam line at the DA Phi NE Beam Test Facility

Author

Cattaneo, P. W., Argan, A., Boffelli, F., Bulgarelli, A., Buonomo, B., Chen, A. W., D'Ammando, F., Foggetta, L., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Longo, F., Marisaldi, M., Mazzitelli, G., Pellizzoni, A., Prest, Michela, Pucella, G., Quintieri, L., Rappoldi, A., Tavani, M., Trifoglio, M., Trois, A., Valente, P., Vallazza, E., Vercellone, S., Zambra, A., Barbiellini, G., Caraveo, P., Cocco, V., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Donnarumma, I., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Mastropietro, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pacciani, L., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Rapisarda, M., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Vittorini, V., Zanello, D., Colafrancesco, S., Giommi, P., Pittori, C., Santolamazza, P., Verrecchia, F., Salotti, L., Cattaneo PW, Argan A, Boffelli F, Bulgarelli A, Buonomo B, Chen AW, DAmmando F, Foggetta L, Froysland T, Fuschino F, Galli M, Gianotti F, Giuliani A, Longo F, Marisaldi M, Mazzitelli G, Pellizzoni A, Prest M, Pucella G, Quintieri L, Rappoldi A, Tavani M, Trifoglio M, Trois A, Valente P, Vallazza E, Vercellone S, Zambra A, Barbiellini G, Caraveo P, Cocco V, Costa E, De Paris G, Del Monte E, Di Cocco G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Mastropietro M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pacciani L, Perotti F, Piano G, Picozza P, Pilia M, Porrovecchio G, Rapisarda M, Rubini A, Sabatini S, Soffitta P, Striani E, Vittorini V, Zanello D, Colafrancesco S, Giommi P, Pittori C, Santolamazza P, Verrecchia F, and Salotti L

Subjects
photon tagged beam, Gamma Ray Imaging Detector, Physics::Instrumentation and Detectors, Astrophysics::High Energy Astrophysical Phenomena, AGILE satellite, Electron and positron beam, Photon beam, silicon tracker, Beam Test Facility, bremsstrahlung, Position-sensitive detector
Abstract

At the core of the AGILE scientific instrument, designed to operate on a satellite, there is the Gamma Ray Imaging Detector (GRID) consisting of a Silicon Tracker (ST), a Cesium Iodide Mini-Calorimeter and an Anti-Coincidence system of plastic scintillator bars. The ST needs an on-ground calibration with a gamma-ray beam to validate the simulation used to calculate the energy response function and the effective area versus the energy and the direction of the gamma rays. A tagged gamma-ray beam line was designed at the Beam Test Facility (BTF) of the INFN Laboratori Nazionali of Frascati (LNF), based on an electron beam generating gamma-rays through bremsstrahlung in a position-sensitive target. The gamma-ray energy is deduced by difference with the post-bremsstrahlung electron energy [1,2]. The electron energy is measured by a spectrometer consisting of a dipole magnet and an array of position sensitive silicon strip detectors, the Photon Tagging System (PTS). The use of the combined BTF-FTS system as tagged photon beam requires understanding the efficiency of gamma-ray tagging, the probability of fake tagging, the energy resolution andthe relation of the PTS hit position versus the gamma-ray energy. This paper describes this study comparing data taken during the AGILE calibration occurred in 2005 with simulation. (C) 2012 Elsevier B.V. All rights reserved.

Published
2012

2. High spatial resolution correlation of AGILE TGFs and global lightning activity above the equatorial belt

Author

Fuschino F, Marisaldi M, Labanti C, Barbiellini G, Del Monte E, Bulgarelli A, Trifoglio M, Gianotti F, Galli M, Argan A, Trois A, Tavani M, Moretti E, Giuliani A, Longo F, Costa E, Caraveo P, Cattaneo PW, Chen A, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Lapshov I, Lazzarotto F, Lipari P, Mereghetti S, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Piano G, Pilia M, Prest M, Pucella G, Rapisarda M, Rappoldi A, Rubini A, Sabatini S, Soffitta P, Striani E, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Antonelli LA, Colafrancesco S, Cutini S, Giommi P, Lucarelli F, Pittori C, Santolamazza P, Verrecchia F, Salotti L., D'AMMANDO, FILIPPO, F., Fuschino, M., Marisaldi, C., Labanti, G., Barbiellini, Monte, E., A., Bulgarelli, M., Trifoglio, F., Gianotti, M., Galli, A., Argan, A., Troi, M., Tavani, E., Moretti, A., Giuliani, Longo, Francesco, E., Costa, P., Caraveo, P. W., Cattaneo, A., Chen, F., D'Ammando, Paris, G., Cocco, G., Persio, G., I., Donnarumma, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, I., Lapshov, F., Lazzarotto, P., Lipari, S., Mereghetti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, G., Piano, M., Pilia, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Soffitta, E., Striani, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, L. A., Antonelli, S., Colafrancesco, S., Cutini, P., Giommi, F., Lucarelli, C., Pittori, P., Santolamazza, F., Verrecchia, L., Salotti, Fuschino F, Marisaldi M, Labanti C, Barbiellini G, Del Monte E, Bulgarelli A, Trifoglio M, Gianotti F, Galli M, Argan A, Trois A, Tavani M, Moretti E, Giuliani A, Longo F, Costa E, Caraveo P, Cattaneo PW, Chen A, DAmmando F, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Lapshov I, Lazzarotto F, Lipari P, Mereghetti S, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Piano G, Pilia M, Prest M, Pucella G, Rapisarda M, Rappoldi A, Rubini A, Sabatini S, Soffitta P, Striani E, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Antonelli LA, Colafrancesco S, Cutini S, Giommi P, Lucarelli F, Pittori C, Santolamazza P, Verrecchia F, and Salotti L

Subjects
AGILE satellite, terrestrial gamma ray flashes, CsI calorimeter, satellite optical observations, global lightning, Atmospheric Processes: Lightning, Lightning [Atmospheric Processes], Atmospheric Processes: Atmospheric electricity, AGILE, TGF, global lightning activity, Atmospheric electricity [Atmospheric Processes]
Abstract

The AGILE satellite detects Terrestrial Gamma-ray Flashes (TGFs) in the 0.35-100 MeV energy range using its Mini-Calorimeter (MCAL) instrument with an average detection rate of 10 TGFs/month. Thanks to its Low Earth Orbit with only 2.5 degree of inclination, AGILE guarantees an unprecedented exposure above the equator, where both lightning activity and TGF detection peak. Here we report the comparison between the AGILE TGFs detected between March 2009 and February 2010 and full climatology lightning worldwide distribution based on satellite optical observations from LIS (Lightning Imaging Sensor) and OTD (Optical Transient Detector) instruments. This approach is complementary to the one-to-one TGF/lightning correlations by ground-based sferics measurements. Based on mono and bi-dimensional Kolmogorov-Smirnov tests, we show that the AGILE TGFs and time-averaged global lightning in the equatorial area are not drawn from the same distribution. However, we find significant regional differences in the degree of correlation as well as in the TGF/lightning ratio. In the case of south east Asia we find a 87% probability for the TGF and lightning being samples of the same distribution. This result supports the idea that the physical conditions at play in TGF generation can have strong geographical and climatological modulation. Based on the assumption that the observed range of TGF/flash ratio holds at all latitudes we can estimate a global rate of (N) over dot similar or equal to 220 divided by 570 TGFs per day. The observed TGF/flash geographical modulation as well as the TGF global rate estimate are in agreement with previous observations. Citation: Fuschino, F., et al. (2011), High spatial resolution correlation of AGILE TGFs and global lightning activity above the equatorial belt, Geophys. Res. Lett., 38, L14806, doi:10.1029/2011GL047817.

Published
2011

3. Detection of terrestrial gamma ray flashes up to 40 MeV by the AGILE satellite

Author

Marisaldi, M., Fuschino, F., Labanti, C., Galli, M., Longo, Francesco, Monte, E. D., Barbiellini, G., Tavani, M., Giuliani, A., Moretti, E., Vercellone, S., Costa, E., Cutini, S., Donnarumma, I., Evangelista, Y., Feroci, M., Lapshov, I., Lazzarotto, F., Lipari, P., Mereghetti, S., Pacciani, L., Rapisarda, M., Soffitta, P., Trifoglio, M., Argan, A., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A., Cocco, V., D'Ammando, F., Paris, G. D., Cocco, G. D., Persio, G. D., Ferrari, A., Fiorini, M., Froysland, T., Gianotti, F., Morselli, A., Pellizzoni, A., Perotti, F., Picozza, P., Piano, G., Pilia, M., Prest, M., Pucella, G., Rappoldi, A., Rubini, A., Sabatini, S., Striani, E., Trois, A., Vallazza, E., Vittorini, V., Zambra, A., Zanello, D., Antonelli, L. A., Colafrancesco, S., Gasparrini, D., Giommi, P., Pittori, C., Preger, B., Santolamazza, P., Verrecchia, F., Salotti, L., Marisaldi M, Fuschino F, Labanti C, Galli M, Longo F, Del Monte E, Barbiellini G, Tavani M, Giuliani A, Moretti E, Vercellone S, Costa E, Cutini S, Donnarumma I, Evangelista Y, Feroci M, Lapshov I, Lazzarotto F, Lipari P, Mereghetti S, Pacciani L, Rapisarda M, Soffitta P, Trifoglio M, Argan A, Boffelli F, Bulgarelli A, Caraveo P, Cattaneo PW, Chen A, Cocco V, DAmmando F, De Paris G, Di Cocco G, Di Persio G, Ferrari A, Fiorini M, Froysland T, Gianotti F, Morselli A, Pellizzoni A, Perotti F, Picozza P, Piano G, Pilia M, Prest M, Pucella G, Rappoldi A, Rubini A, Sabatini S, Striani E, Trois A, Vallazza E, Vittorini V, Zambra A, Zanello D, Antonelli LA, Colafrancesco S, Gasparrini D, Giommi P, Pittori C, Preger B, Santolamazza P, Verrecchia F, Salotti L, M., Marisaldi, F., Fuschino, C., Labanti, M., Galli, Longo, Francesco, E. D., Monte, G., Barbiellini, M., Tavani, A., Giuliani, E., Moretti, S., Vercellone, E., Costa, S., Cutini, I., Donnarumma, Y., Evangelista, M., Feroci, I., Lapshov, F., Lazzarotto, P., Lipari, S., Mereghetti, L., Pacciani, M., Rapisarda, P., Soffitta, M., Trifoglio, A., Argan, F., Boffelli, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, A., Chen, V., Cocco, F., D'Ammando, G. D., Pari, G. D., Cocco, G. D., Persio, A., Ferrari, M., Fiorini, T., Froysland, F., Gianotti, A., Morselli, A., Pellizzoni, F., Perotti, P., Picozza, G., Piano, M., Pilia, M., Prest, G., Pucella, A., Rappoldi, A., Rubini, S., Sabatini, E., Striani, A., Troi, E., Vallazza, V., Vittorini, A., Zambra, D., Zanello, L. A., Antonelli, S., Colafrancesco, D., Gasparrini, P., Giommi, C., Pittori, B., Preger, P., Santolamazza, F., Verrecchia, and L., Salotti

Subjects
Agile, terrestrial gamma ray flashes, minicalorimeter, High Energy Gamma-ray Astronomy, AGILE satellite, Terrestrial Gamma-ray Flashes, terrestrial gamma ray flashes, AGILE satellite
Abstract

We report the detection by the Astrorivelatore Gamma a Immagini Leggero (AGILE) satellite of terrestrial gamma ray flashes (TGFs) obtained with the minicalorimeter (MCAL) detector operating in the energy range 0.3-100 MeV. We select events typically lasting a few milliseconds with spectral and directional selections consistent with the TGF characteristics previously reported by other space missions. During the period 1 June 2008 to 31 March 2009 we detect 34 high-confidence events showing millisecond durations and a geographical distribution peaked over continental Africa and Southeast Asia. For the first time, AGILE-MCAL detects photons associated with TGF events up to 40 MeV. We determine the cumulative spectral properties of the spectrum in the range 0.5-40 MeV, which can be effectively described by a Bremsstrahlung spectrum. We find that both the TGF cumulative spectral properties and their geographical distribution are in good agreement with the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) results.

Published
2010

4. The characterization of the distant blazar GB6 J1239+0443 from flaring and low activity periods

Author

Pacciani, L., Donnarumma, I., Denney, K. D., Assef, R. J., Ikejiri, Y., Yamanaka, M., Uemura, M., Domingo, A., Giommi, P., Tarchi, A., Verrecchia, F., Longo, F., Rainó, S., Giusti, M., Vercellone, S., Chen, A. W., Striani, E., Vittorini, V., Tavani, M., Bulgarelli, A., Giuliani, A., Pucella, G., Argan, A., Barbiellini, G., Caraveo, P., Cattaneo, P. W., Colafrancesco, S., Costa, E., De Paris, G., Del Monte, E., Di Cocco, G., Evangelista, Y., Ferrari, A., Feroci, M., Fiorini, M., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Marisaldi, M., Mereghetti, S., Morelli, E., Moretti, E., Morselli, A., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Prest, M., Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Trifoglio, M., Trois, A., Vallazza, E., Zanello, D., Pittori, C., Santolamazza, P., Lucarelli, F., Salotti, L., Valentini, G., L., Pacciani, I., Donnarumma, K. D., Denney, R. J., Assef, Y., Ikejiri, M., Yamanaka, M., Uemura, A., Domingo, P., Giommi, A., Tarchi, F., Verrecchia, Longo, Francesco, S., Raino, M., Giusti, S., Vercellone, A. W., Chen, E., Striani, V., Vittorini, M., Tavani, A., Bulgarelli, A., Giuliani, G., Pucella, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, S., Colafrancesco, E., Costa, Paris, G., E. D., Monte, G. D., Cocco, Y., Evangelista, A., Ferrari, M., Feroci, M., Fiorini, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, D., Zanello, C., Pittori, P., Santolamazza, F., Lucarelli, L., Salotti, and G., Valentini

Subjects
High Energy Astrophysical Phenomena (astro-ph.HE), astro-ph.HE, Cosmology and Nongalactic Astrophysics (astro-ph.CO), gamma-ray flaring, general [quasars], Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, FOS: Physical sciences, individual: GB6 J1239+0443 [galaxies], Astrophysics::Cosmology and Extragalactic Astrophysics, AGILE satellite, radiation mechanisms, black hole, blazar, radiation mechanisms: non-thermal, non-thermal [radiation mechanisms], galaxies: individual: GB6 J1239+0443, quasars: general, active [galaxies], astro-ph.CO, Astrophysics - High Energy Astrophysical Phenomena, Astrophysics::Galaxy Astrophysics, Astrophysics - Cosmology and Nongalactic Astrophysics
Abstract

In 2008 AGILE and Fermi detected gamma-ray flaring activity from the unidentified EGRET source 3EG J1236+0457, recently associated with a flat spectrum radio quasar GB6 J1239+0443 at z=1.762. The optical counterpart of the gamma-ray source underwent a flux enhancement of a factor 15-30 in 6 years, and of ~10 in six months. We interpret this flare-up in terms of a transition from an accretion-disk dominated emission to a synchrotron-jet dominated one. We analysed a Sloan Digital Sky Survey (SDSS) archival optical spectrum taken during a period of low radio and optical activity of the source. We estimated the mass of the central black hole using the width of the CIV emission line. In our work, we have also investigated SDSS archival optical photometric data and UV GALEX observations to estimate the thermal-disk emission contribution of GB6 J1239+0443. Our analysis of the gamma-ray data taken during the flaring episodes indicates a flat gamma-ray spectrum, with an extension of up to 15 GeV, with no statistically-relevant sign of absorption from the broad line region, suggesting that the blazar-zone is located beyond the broad line region. This result is confirmed by the modeling of the broad-band spectral energy distribution (well constrained by the available multiwavelength data) of the flaring activity periods and by the accretion disk luminosity and black hole mass estimated by us using archival data., Comment: 30 pages, 7 figures, 4 tables MNRAS Accepted on 2012 June 18

Published
2012

5. AGILE detection of extreme gamma-ray activity from the blazar PKS 1510-089 during March 2009

Author

D'Ammando, F., Raiteri, C. M., Villata, M., Romano, P., Pucella, G., Krimm, H. A., Covino, S., Orienti, M., Giovannini, G., Vercellone, S., Pian, E., Donnarumma, I., Vittorini, V., Tavani, M., Argan, A., Barbiellini, G., Boffelli, F., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Chen, A. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Ferrari, A., Fiorini, M., Froysland, T., Frutti, M., Fuschino, F., Galli, M., Gianotti, F., Giuliani, A., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Marisaldi, M., Mereghetti, S., Morselli, A., Pacciani, L., Pellizzoni, A., Perotti, F., Piano, G., Picozza, P., Pilia, M., Porrovecchio, G., Prest, Michela, Rapisarda, M., Rappoldi, A., Rubini, A., Sabatini, S., Soffitta, P., Striani, E., Trifoglio, M., Trois, A., Vallazza, E., Zambra, A., Zanello, D., Agudo, I., Aller, H. D., Aller, M. F., Arkharov, A. A., Bach, U., Benitez, E., Berdyugin, A., Blinov, D. A., Buemi, C. S., Chen, W. P., Di Paola, A., Dolci, M., Forne, E., Fuhrmann, L., Gomez, J. L., Gurwell, M. A., Jordan, B., Jorstad, S. G., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O. M., Kurtanidze, S. O., Larionov, V. M., Lahteenmaki, A., Leto, P., Lindfors, E., Marscher, A. P., Mcbreen, B., Mchardy, I. M., Morozova, D. A., Nilsson, K., Pasanen, M., Roca Sogorb, M., Sillanpaa, A., Takalo, L. O., Tornikoski, M., Trigilio, C., Troitsky, I. S., Umana, G., Antonelli, L. A., Colafrancesco, S., Pittori, C., Santolamazza, P., Verrecchia, F., Giommi, P., and Salotti, L.

Subjects
radio quasar PKS 1510-089, AGILE satellite, gamma-ray, observations from UV to hard X-ray and radio
Published
2011

6. THE 2009 DECEMBER GAMMA-RAY FLARE OF 3C 454.3: THE MULTIFREQUENCY CAMPAIGN

Author

L. Salotti, E. Moretti, Mark Gurwell, C. Pittori, M. Tavani, S. Vercellone, V. Vittorini, F. Longo, T. Sakamoto, Martino Marisaldi, A. Morselli, M. Galli, P. Santolamazza, G. Barbiellini P. Caraveo, Elena Pian, C. M. Raiteri, M. Pilia, Francesco Lucarelli, A. Trois, A. Rubini, F. D'Ammando, F. Verrecchia, Michael C. Stroh, M. Prest, F. Perotti, Andrea Tiengo, E. Vallazza, P. W. Cattaneo, M. Feroci, Merja Tornikoski, M. Villata, L. Pacciani, P. Picozza, A. Pellizzoni, E. Costa, E. Del Monte, A. Rappoldi, M. Fiorini, Ryosuke Itoh, P. A. Curran, Masayuki Yamanaka, G. Pucella, F. Lazzarotto, Valeri M. Larionov, C. S. Lin, F. Gianotti, A. C. Sadun, A. Giuliani, V. Cocco, Arnaud Ferrari, P. Lipari, M. Trifoglio, M. Fiocchi, E. Morelli, Andrei Berdyugin, G. Piano, H. A. Krimm, Sandro Mereghetti, L. O. Takalo, A. D. Falcone, S. Colafrancesco, Claudio Labanti, D. Zanello, F. Fuschino, D. Fugazza, G. Di Cocco, M. Rapisarda, A. Argan, Andrea Bulgarelli, Makoto Uemura, P. Giommi, Anne Lähteenmäki, G. De Paris, I. Donnarumma, Y. Evangelista, P. Soffitta, A. W. Chen, Paolo Leto, Hugh D. Aller, E. Striani, Mahito Sasada, I. Lapshov, M. F. Aller, S. Sabatini, Pacciani L, Vittorini V, Tavani M, Fiocchi MT, Vercellone S, DAmmando F, Sakamoto T, Pian E, Raiteri CM, Villata M, Sasada M, Itoh R, Yamanaka M, Uemura M, Striani E, Fugazza D, Tiengo A, Krimm HA, Stroh MC, Falcone AD, Curran PA, Sadun AC, Lahteenmaki A, Tornikoski M, Aller HD, Aller MF, Lin CS, Larionov VM, Leto P, Takalo LO, Berdyugin A, Gurwell MA, Bulgarelli A, Chen AW, Donnarumma I, Giuliani A, Longo F, Pucella G, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, Costa E, De Paris G, Del Monte E, Di Cocco G, Evangelista Y, Ferrari A, Feroci M, Fiorini M, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Marisaldi M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Prest M, Rapisarda M, Rappoldi A, Rubini A, Sabatini S, Soffitta P, Trifoglio M, Trois A, Vallazza E, Zanello D, Colafrancesco S, Pittori C, Verrecchia F, Santolamazza P, Lucarelli F, Giommi P, Salotti L, L., Pacciani, V., Vittorini, M., Tavani, M. T., Fiocchi, S., Vercellone, F., D'Ammando, T., Sakamoto, E., Pian, C. M., Raiteri, M., Villata, M., Sasada, R., Itoh, M., Yamanaka, M., Uemura, E., Striani, D., Fugazza, A., Tiengo, H. A., Krimm, M. C., Stroh, A. D., Falcone, P. A., Curran, A. C., Sadun, A., Lahteenmaki, M., Tornikoski, H. D., Aller, M. F., Aller, C. S., Lin, V. M., Larionov, P., Leto, L. O., Takalo, A., Berdyugin, M. A., Gurwell, A., Bulgarelli, A. W., Chen, I., Donnarumma, A., Giuliani, Longo, Francesco, G., Pucella, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, E., Costa, G. D., Pari, E. D., Monte, G. D., Cocco, Y., Evangelista, A., Ferrari, M., Feroci, M., Fiorini, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, D., Zanello, S., Colafrancesco, C., Pittori, F., Verrecchia, P., Santolamazza, F., Lucarelli, P., Giommi, and L., Salotti

Subjects
Agile, Astrophysics::High Energy Astrophysical Phenomena, media_common.quotation_subject, galaxies: active, Flux, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, gamma-ray source, High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, Spectral line, blazar, law.invention, Accretion disc, multi wavelength observation, law, quasars: general, Blazar, media_common, Physics, galaxies: individual (3C 454.3), Gamma ray, Astronomy and Astrophysics, radiation mechanisms: non-thermal, Wavelength, Space and Planetary Science, Sky, Flare
Abstract

During the month of 2009 December, the blazar 3C 454.3 became the brightest gamma-ray source in the sky, reaching a peak flux F 2000 × 10 -8 photons cm-2 s-1 for E > 100 MeV. Starting in 2009 November intensive multifrequency campaigns monitored the 3C 454 gamma-ray outburst. Here, we report on the results of a two-month campaign involving AGILE, INTEGRAL, Swift/XRT, Swift/BAT, and Rossi XTE for the high-energy observations and Swift/UVOT, KANATA, Goddard Robotic Telescope, and REM for the near-IR/optical/UV data. GASP/WEBT provided radio and additional optical data. We detected a long-term active emission phase lasting 1 month at all wavelengths: in the gamma-ray band, peak emission was reached on 2009 December 2-3. Remarkably, this gamma-ray super-flare was not accompanied by correspondingly intense emission in the optical/UV band that reached a level substantially lower than the previous observations in 2007-2008. The lack of strong simultaneous optical brightening during the super-flare and the determination of the broadband spectral evolution severely constrain the theoretical modeling. We find that the pre- and post-flare broadband behavior can be explained by a one-zone model involving synchrotron self-Compton plus external Compton emission from an accretion disk and a broad-line region. However, the spectra of the 2009 December 2-3 super-flare and of the secondary peak emission on 2009 December 9 cannot be satisfactorily modeled by a simple one-zone model. An additional particle component is most likely active during these states. © 2010. The American Astronomical Society. All rights reserved.

Published
2010
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7. AGILE detection of Cygnus X-3 {\gamma}-ray active states during the period mid-2009/mid-2010

Author

E. Moretti, Maura Pilia, Guy G. Pooley, V. Vittorini, G. De Paris, G. Di Cocco, M. Trifoglio, Alessio Trois, A. Rappoldi, E. Vallazza, L. Salotti, F. Perotti, Francesco Lazzarotto, Francesco Longo, C. Pittori, A. Zambra, Paolo Soffitta, A. Morselli, A. Giuliani, Danny Steeghs, A. Pellizzoni, Y. Evangelista, I. Donnarumma, V. Cocco, Marco Tavani, D. Zanello, T. Contessi, M. Galli, Piergiorgio Picozza, S. Vercellone, E. Striani, Fulvio Gianotti, G. Piano, Michael L. McCollough, S. Sabatini, Sergio Colafrancesco, F. Verrecchia, P. Santolamazza, I. Lapshov, Alda Rubini, N. A. Nizhelskij, E. Del Monte, Sandro Mereghetti, Paolo Giommi, P. W. Cattaneo, N. Lavonen, A. W. Chen, Anne Lähteenmäki, Alessio Aboudan, Massimo Rapisarda, S. A. Trushkin, Guido Barbiellini, Joni Tammi, M. Prest, D. Hannikainen, Marco Feroci, Luigi Pacciani, C. Labanti, Filippo D'Ammando, A. Argan, Andrea Bulgarelli, Martino Marisaldi, Enrico Costa, M. Giusti, Karri I. I. Koljonen, Ennio Morelli, Massimiliano Fiorini, P. A. Caraveo, G. Pucella, Paolo Lipari, F. Lucarelli, F. Fuschino, Riccardo Campana, A., Bulgarelli, M., Tavani, A. W., Chen, Y., Evangelista, M., Trifoglio, F., Gianotti, G., Piano, S., Sabatini, E., Striani, G., Pooley, S., Trushkin, N. A., Nizhelskij, M., Mccollough, K. I., I., D., Hannikainen, A., L\ahteenm\aki, J., Tammi, N., Lavonen, D., Steegh, A., Aboudan, A., Argan, G., Barbiellini, R., Campana, P., Caraveo, P. W., Cattaneo, V., Cocco, T., Contessi, E., Costa, F., D'Ammando, Monte, E., Paris, G., Cocco, G., I., Donnarumma, M., Feroci, M., Fiorini, F., Fuschino, M., Galli, A., Giuliani, M., Giusti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, A., Rubini, P., Soffitta, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, P., Giommi, C., Pittori, F., Verrecchia, P., Santolamazza, F., Lucarelli, S., Colafrancesco, L., Salotti, Bulgarelli A, Tavani M, Chen AW, Evangelista Y, Trifoglio M, Gianotti F, Piano G, Sabatini S, Striani E, Pooley G, Trushkin S, Nizhelskij NA, McCollough M, Koljonen KII, Hannikainen D, Lahteenmaki A, Tammi J, Lavonen N, Steeghs D, Aboudan A, Argan A, Barbiellini G, Campana R, Caraveo P, Cattaneo PW, Cocco V, Contessi T, Costa E, DAmmando F, Del Monte E, De Paris G, Di Cocco G, Donnarumma I, Feroci M, Fiorini M, Fuschino F, Galli M, Giuliani A, Giusti M, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Pilia M, Prest M, Pucella G, Rapisarda M, Rappoldi A, Rubini A, Soffitta P, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Giommi P, Pittori C, Verrecchia F, Santolamazza P, Lucarelli F, Colafrancesco S, Salotti L, Anne Lähteenmäki Group, Aalto-yliopisto, and Aalto University

Subjects
gamma-rays: stars, education, Flux, Astrophysics, 01 natural sciences, gamma-rays: stars – stars: individual: Cygnus X-3, stars [gamma-rays], Acceleration, Astrophysical jet, 0103 physical sciences, MAGIC (telescope), microquasar, Cygnus X-3, 010303 astronomy & astrophysics, QB, stars: individual: Cygnus X-3, Physics, star [gamma-rays], 010308 nuclear & particles physics, AGILE satellite, gamma rays, Gamma ray, Astronomy and Astrophysics, Particle acceleration, Wavelength, Space and Planetary Science, individual: Cygnus X-3 [stars], Production (computer science), Astrophysics - High Energy Astrophysical Phenomena
Abstract

Cygnus X-3 (Cyg X-3) is a well-known microquasar producing variable emission at all wavelengths. Cyg X-3 is a prominent X-ray binary producing relativistic jets, and studying its high energy emission is crucial for the understanding of the fundamental acceleration processes in accreting compact objects. Aims. Our goal is to study extreme particle acceleration and {\gamma}-ray production above 100 MeV during special spectral states of Cyg X- 3 usually characterized by a low hard X-ray flux and enhanced soft X-ray states. We observed Cyg X-3 with the AGILE satellite in extended time intervals from 2009 Jun.-Jul., and 2009 Nov.-2010 Jul. We report here the results of the AGILE {\gamma}-ray monitoring of Cyg X-3 as well as the results from extensive multiwavelength campaigns involving radio (RATAN-600, AMI-LA and Mets\"{a}hovi Radio Observatories) and X-ray monitoring data (XTE and Swift). We detect a series of repeated {\gamma}-ray flaring activity from Cyg X-3 that correlate with the soft X-ray states and episodes of decreasing or non-detectable hard X-ray emission. Furthermore, we detect {\gamma}-ray enhanced emission that tends to be associated with radio flares greater than 1 Jy at 15 GHz, confirming a trend already detected in previous observations. The source remained active above 100 MeV for an extended period of time (almost 1.5 months in 2009 Jun.-Jul. and 1 month in 2010 May). We study in detail the short timescale {\gamma}-ray flares that occurred before or near the radio peaks. Our results confirm the transient nature of the extreme particle acceleration from the microquasar Cyg X-3. A series of repeated {\gamma}-ray flares shows correlations with radio and X-ray emission confirming a well established trend of emission. We compare our results with Fermi-LAT and MAGIC TeV observations of Cyg X-3., Comment: 16 pages, 8 figures, 7 tables; A&A (2011)

Published
2011

8. The AGILE observations of the hard and bright GRB 100724B

Author

P. Santolamazza, M. Galli, Piergiorgio Picozza, S. Cutini, F. Verrecchia, V. Vittorini, Paolo Giommi, M. Trifoglio, F. Perotti, E. Striani, Sandro Mereghetti, I. Lapshov, P. W. Cattaneo, A. W. Chen, Elena Moretti, Fulvio Gianotti, M. Prest, E. Del Monte, Francesco Lazzarotto, A. Rappoldi, E. Vallazza, G. Di Cocco, Marco Feroci, Filippo D'Ammando, Paolo Soffitta, Luigi Pacciani, Guido Barbiellini, Paolo Lipari, I. Donnarumma, C. Labanti, Francesco Longo, A. Morselli, Maura Pilia, A. Argan, Andrea Bulgarelli, Alessio Trois, P. A. Caraveo, Enrico Costa, S. Vercellone, G. Piano, Marco Tavani, S. Sabatini, Martino Marisaldi, L. A. Antonelli, L. Salotti, Massimo Rapisarda, Y. Evangelista, A. Giuliani, C. Pittori, A. Pellizzoni, G. Pucella, F. Fuschino, Del Monte E, Barbiellini G, Donnarumma I, Fuschino F, Giuliani A, Longo F, Marisaldi M, Pucella G, Tavani M, Trifoglio M, Trois A, Argan A, Bulgarelli A, Caraveo P, Cattaneo PW, Chen AW, Costa E, DAmmando F, Di Cocco G, Evangelista Y, Feroci M, Galli M, Gianotti F, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Mereghetti S, Moretti E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Prest M, Rapisarda M, Rappoldi A, Sabatini S, Soffitta P, Striani E, Vallazza E, Vercellone S, Vittorini V, Antonelli LA, Cutini S, Pittori C, Santolamazza P, Verrecchia F, Giommi P, Salotti L, E., Del Monte, G., Barbiellini, I., Donnarumma, F., Fuschino, A., Giuliani, Longo, Francesco, M., Marisaldi, G., Pucella, M., Tavani, M., Trifoglio, A., Troi, A., Argan, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, A. W., Chen, E., Costa, F., D'Ammando, Cocco, G., Y., Evangelista, M., Feroci, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, S., Mereghetti, E., Moretti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, S., Sabatini, P., Soffitta, E., Striani, E., Vallazza, S., Vercellone, V., Vittorini, L. A., Antonelli, S., Cutini, C., Pittori, P., Santolamazza, F., Verrecchia, P., Giommi, and L., Salotti

Subjects
Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Context (language use), Astrophysics, gamma-ray burst: individual: GRB 100724B, individual: GRB 100724B [gamma-ray burst], emission at MeV and GeV, gamma ray burst, symbols.namesake, Observatory, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Cross-correlation, AGILE satellite, Astronomy and Astrophysics, gamma rays: general, gamma rays: general / gamma-ray burst: individual: GRB 100724B, Lorentz factor, Space and Planetary Science, symbols, Gamma-ray burst, Interplanetary spaceflight, Astrophysics - High Energy Astrophysical Phenomena, Event (particle physics), general [gamma rays], Fermi Gamma-ray Space Telescope
Abstract

The observation of Gamma Ray Bursts (GRBs) in the gamma-ray band has been advanced by the AGILE and Fermi satellites after the era of the Compton Gamma-Ray Observatory. AGILE and Fermi are showing that the GeV-bright GRBs share a set of common features, particularly the high fluence from the keV up to the GeV energy bands, the high value of the minimum Lorentz factor, the presence of an extended emission of gamma-rays, often delayed with respect to lower energies, and finally the possible presence of multiple spectral components. GRB 100724B, localised in a joint effort by Fermi and the InterPlanetary Newtork, is the brightest burst detected in gamma-rays so far by AGILE. Characteristic features of GRB 100724B are the simultaneous emissions at MeV and GeV, without delayed onset nor time lag as shown by the analysis of the cross correlation function, and the significant spectral evolution in hard X-rays over the event duration. In this paper we show the analysis of the AGILE data of GRB 100724B and we discuss its features in the context of the bursts observed so far in gamma-rays and the recently proposed models., 8 pages, 5 figures. Accepted for publication by A&A. Final version after the correction by the language editor

Published
2011

9. Study of the γ-ray source 1AGL J2022+4032 in the Cygnus region

Author

F. Longo, Elsa Beatriz Giacani, G. Piano, Arnaud Ferrari, A. Zambra, F. D'Ammando, C. Pittori, M. Feroci, M. Fiorini, P. Picozza, M. Rapisarda, G. De Paris, Gloria Mabel Dubner, A. Pellizzoni, E. Costa, E. Del Monte, G. Pucella, V. Vittorini, F. Perotti, A. Trois, M. Trifoglio, A. Morselli, M. Tavani, E. Vallazza, F. Gianotti, P. A. Caraveo, A. Argan, M. Pilia, A. Giuliani, Francesco Lucarelli, P. Soffitta, Andrea Bulgarelli, F. Lazzarotto, F. Fuschino, S. Vercellone, P. Lipari, P. Santolamazza, A. Rappoldi, E. Scalise, E. Striani, M. Giusti, L. Pacciani, P. W. Cattaneo, A. W. Chen, L. A. Antonelli, M. Galli, F. Verrecchia, M. Prest, S. Sabatini, P. Giommi, E. Moretti, Claudio Labanti, L. Salotti, D. Zanello, G. Di Cocco, Sandro Mereghetti, I. Donnarumma, Y. Evangelista, S. Colafrancesco, Martino Marisaldi, G. Barbiellini, A. W., Chen, G., Piano, M., Tavani, A., Troi, G., Dubner, E., Giacani, A., Argan, G., Barbiellini, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, E., Costa, F., D'Ammando, Paris, G., Monte, E., Cocco, G., I., Donnarumma, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, F., Fuschino, M., Galli, F., Gianotti, A., Giuliani, M., Giusti, C., Labanti, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, E., Moretti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, S., Sabatini, E., Scalise, P., Soffitta, E., Striani, M., Trifoglio, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, C., Pittori, P., Giommi, F., Verrecchia, F., Lucarelli, P., Santolamazza, S., Colafrancesco, L. A., Antonelli, L., Salotti, Chen AW, Piano G, Tavani M, Trois A, Dubner G, Giacani E, Argan A, Barbiellini G, Bulgarelli A, Caraveo P, Cattaneo PW, Costa E, DAmmando F, De Paris G, Del Monte E, Di Cocco G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Fuschino F, Galli M, Gianotti F, Giuliani A, Giusti M, Labanti C, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mereghetti S, Moretti E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Pilia M, Prest M, Pucella G, Rapisarda M, Rappoldi A, Sabatini S, Scalise E, Soffitta P, Striani E, Trifoglio M, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Pittori C, Giommi P, Verrecchia F, Lucarelli F, Santolamazza P, Colafrancesco S, Antonelli LA, and Salotti L

Subjects
pulsars: individual: 1FGL J2021.5+4026, Astrophysics::High Energy Astrophysical Phenomena, Ciencias Físicas, pulsars: individual: 1AGL J2022+4032, gamma rays: stars, pulsars: individual: LAT PSR J2021+4026, pulsars: individual: 3EG J2020+4017, individual: LAT PSR J2021+4026 [pulsars], Flux, FOS: Physical sciences, Astrophysics, star [gamma rays], law.invention, Telescope, purl.org/becyt/ford/1 [https], Pulsar, law, Blazar, Supernova remnant, individual: 1FGL J2021.5+4026 [pulsars], Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Gamma ray, Astronomy and Astrophysics, individual: 3EG J2020+4017 [pulsars], purl.org/becyt/ford/1.3 [https], Light curve, stars [gamma rays], Astronomía, gamma ray, Space and Planetary Science, AGILE satellite, galactic source, supernova remnant Gamma Cygni, individual: 1AGL J2022+4032 [pulsars], pulsars: individual: 1AGL J2022+4032 / gamma rays: stars / pulsars: individual: 1FGL J2021.5+4026 / pulsars: individual: LAT PSR J2021+4026 / pulsars: individual: 3EG J2020+4017, Astrophysics - High Energy Astrophysical Phenomena, CIENCIAS NATURALES Y EXACTAS, Fermi Gamma-ray Space Telescope
Abstract

Identification of gamma-ray-emitting Galactic sources is a long-standing problem in astrophysics. One such source, 1AGL J2022+4032, coincident with the interior of the radio shell of the supernova remnant Gamma Cygni (SNR G78.2+2.1) in the Cygnus Region, has recently been identified by Fermi as a gamma-ray pulsar, LAT PSR J2021+4026. We present long-term observations of 1AGL J2022+4032 with the AGILE gamma-ray telescope, measuring its flux and light curve. We compare the light curve of 1AGL J2022+4032 with that of 1AGL J2021+3652 (PSR J2021+3651), showing that the flux variability of 1AGL J2022+4032 appears to be greater than the level predicted from statistical and systematic effects and producing detailed simulations to estimate the probability of the apparent observed variability. We evaluate the possibility that the gamma-ray emission may be due to the superposition of two or more point sources, some of which may be variable, considering a number of possible counterparts. We consider the possibility of a nearby X-ray quiet microquasar contributing to the flux of 1AGL J2022+4032 to be more likely than the hypotheses of a background blazar or intrinsic gamma-ray variabilty of LAT PSR J2021+4026., 7 pages, 7 figures, accepted for publication in Astronomy & Astrophysics

Published
2010

10. Direct Evidence for Hadronic Cosmic-Ray Acceleration in the Supernova Renmant IC 443

Author

C. Pittori, Marco Feroci, F. Fuschino, Luigi Pacciani, Paolo Soffitta, G. De Paris, A. Giuliani, E. Scalise, Filippo D'Ammando, V. Cocco, M. Mastropietro, E. Del Monte, V. Vittorini, Arnaud Ferrari, Paolo Lipari, M. Trifoglio, Y. Evangelista, S. Vercellone, F. Perotti, Francesco Lazzarotto, P. Santolamazza, A. Zambra, A. Pellizzoni, G. Di Cocco, E. Striani, I. Lapshov, Fulvio Gianotti, I. Donnarumma, Martino Marisaldi, L. Salotti, Elena Moretti, Alda Rubini, P. W. Cattaneo, A. Rappoldi, A. W. Chen, P. Picozza, P. Giommi, Massimo Rapisarda, G. Pucella, F. Longo, D. Zanello, A. Argan, Andrea Bulgarelli, T. Contessi, Enrico Costa, Claudio Labanti, L. A. Antonelli, G. Piano, P. A. Caraveo, M. Galli, F. Verrecchia, Sandro Mereghetti, A. Morselli, S. Colafrancesco, M. Prest, Alessio Trois, M. Pilia, Marco Tavani, S. Sabatini, Ennio Morelli, G. Barbiellini, E. Vallazza, M., Tavani, A., Giuliani, A. W., Chen, A., Argan, G., Barbiellini, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, V., Cocco, T., Contessi, F., D'Ammando, E., Costa, G. D., Pari, E. D., Monte, G. D., Cocco, I., Donnarumma, Y., Evangelista, A., Ferrari, M., Feroci, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, M., Mastropietro, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, G., Pucella, M., Prest, M., Rapisarda, A., Rappoldi, E., Scalise, A., Rubini, S., Sabatini, E., Striani, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, C., Pittori, F., Verrecchia, P., Santolamazza, P., Giommi, S., Colafrancesco, L. A., Antonelli, L., Salotti, Tavani M, Giuliani A, Chen AW, Argan A, Barbiellini G, Bulgarelli A, Caraveo P, Cattaneo PW, Cocco V, Contessi T, DAmmando F, Costa E, De Paris G, Del Monte E, Di Cocco G, Donnarumma I, Evangelista Y, Ferrari A, Feroci M, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mastropietro M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Pucella G, Prest M, Rapisarda M, Rappoldi A, Scalise E, Rubini A, Sabatini S, Striani E, Soffitta P, Trifoglio M, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Pittori C, Verrecchia F, Santolamazza P, Giommi P, Colafrancesco S, Antonelli LA, and Salotti L

Subjects
Agile, Photon, Supernova Remnants, Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Cosmic ray, Electron, Astrophysics, High Energy Gamma-ray Astronomy, gamma ray production, supernova, Supernova remnant, Astrophysics::Galaxy Astrophysics, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Molecular cloud, AGILE satellite, Gamma ray, Astronomy and Astrophysics, Astrophysics - Astrophysics of Galaxies, Supernova, Space and Planetary Science, Astrophysics of Galaxies (astro-ph.GA), Astrophysics - High Energy Astrophysical Phenomena, cosmic rays – gamma rays: general – ISM: supernova remnants – supernovae: general – supernovae: individual (IC 443)
Abstract

The Supernova Remnant (SNR) IC 443 is an intermediate-age remnant well known for its radio, optical, X-ray and gamma-ray energy emissions. In this Letter we study the gamma-ray emission above 100 MeV from IC 443 as obtained by the AGILE satellite. A distinct pattern of diffuse emission in the energy range 100 MeV-3 GeV is detected across the SNR with its prominent maximum (source "A") localized in the Northeastern shell with a flux F = (47 \pm 10) 10^{-8} photons cm^{-2} s^{-1} above 100 MeV. This location is the site of the strongest shock interaction between the SNR blast wave and the dense circumstellar medium. Source "A" is not coincident with the TeV source located 0.4 degree away and associated with a dense molecular cloud complex in the SNR central region. From our observations, and from the lack of detectable diffuse TeV emission from its Northeastern rim, we demonstrate that electrons cannot be the main emitters of gamma-rays in the range 0.1-10 GeV at the site of the strongest SNR shock. The intensity, spectral characteristics, and location of the most prominent gamma-ray emission together with the absence of co-spatial detectable TeV emission are consistent only with a hadronic model of cosmic-ray acceleration in the SNR. A high-density molecular cloud (cloud "E") provides a remarkable "target" for nucleonic interactions of accelerated hadrons: our results show enhanced gamma-ray production near the molecular cloud/shocked shell interaction site. IC 443 provides the first unambiguous evidence of cosmic-ray acceleration by SNRs., Comment: 5 pages, 2 figures; accepted by ApJLetters on Jan 21, 2010

Published
2010
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11. A year-long AGILE observation of Cygnus X-1 in hard spectral state

Author

A. W. Chen, Francesco Lazzarotto, A. Morselli, Marco Feroci, Luigi Pacciani, E. Striani, S. Vercellone, M. Prest, C. Pittori, I. Lapshov, I. Donnarumma, E. Del Monte, Sandro Mereghetti, A. Argan, M. Galli, P. W. Cattaneo, Piergiorgio Picozza, Massimo Rapisarda, F. Fuschino, Andrea Bulgarelli, F. Perotti, A. Pellizzoni, G. Di Cocco, F. Verrecchia, Enrico Costa, Elena Moretti, Filippo D'Ammando, G. Piano, A. Rappoldi, E. Vallazza, S. Cutini, A. Giuliani, P. A. Caraveo, L. Salotti, Paolo Soffitta, Claudio Labanti, A. Zambra, Francesco Longo, L. A. Antonelli, Guido Barbiellini, Martino Marisaldi, Paolo Lipari, P. Santolamazza, Paolo Giommi, Marco Tavani, S. Sabatini, V. Vittorini, M. Trifoglio, Maura Pilia, Alessio Trois, Fulvio Gianotti, B. Preger, F. Boffelli, Y. Evangelista, G. Pucella, Del Monte E, Feroci M, Evangelista Y, Costa E, Donnarumma I, Lapshov I, Lazzarotto F, Pacciani L, Rapisarda M, Soffitta P, Argan A, Barbiellini G, Boffelli F, Bulgarelli A, Caraveo P, Cattaneo PW, Chen A, DAmmando F, Di Cocco G, Fuschino F, Galli M, Gianotti F, Giuliani A, Labanti C, Lipari P, Longo F, Marisaldi M, Mereghetti S, Moretti E, Morselli A, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Prest M, Pucella G, Rappoldi A, Sabatini S, Striani E, Tavani M, Trifoglio M, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Antonelli LA, Cutini S, Pittori C, Preger B, Santolamazza P, Verrecchia F, Giommi P, Salotti L, E. D., Monte, M., Feroci, Y., Evangelista, E., Costa, I., Donnarumma, I., Lapshov, F., Lazzarotto, L., Pacciani, M., Rapisarda, P., Soffitta, A., Argan, G., Barbiellini, F., Boffelli, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, A., Chen, F., D'Ammando, G. D., Cocco, F., Fuschino, M., Galli, F., Gianotti, A., Giuliani, C., Labanti, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, G., Pucella, A., Rappoldi, S., Sabatini, E., Striani, M., Tavani, M., Trifoglio, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, L. A., Antonelli, S., Cutini, C., Pittori, B., Preger, P., Santolamazza, F., Verrecchia, P., Giommi, and L., Salotti

Subjects
Agile, Black Holes, Astrophysics::High Energy Astrophysical Phenomena, Hadron, Phase (waves), Flux, FOS: Physical sciences, Astrophysics, cignus, High Energy Gamma-ray Astronomy, X-ray, binaries, silicon detector, Range (statistics), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Autocorrelation, Gamma ray, Static timing analysis, Astronomy and Astrophysics, stars: individual: Cyg X-1, gamma rays: observations, X-rays: binaries, X-rays: general, Space and Planetary Science, AGILE satellite, Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing)
Abstract

We present the observation of Cyg X-1 in hard spectral state performed during the AGILE Science Verification Phase and Observing Cycle 1 in hard X-rays (with SuperAGILE) and gamma rays (with the GRID) and lasting for about 160 days with a live time of $\sim 6$ Ms. We investigate the variability of Cyg X-1 in hard X-rays at different timescales, from $\sim 300$ s up to one day, and we apply different tools of timing analysis, such as the autocorrelation function, the first order structure function and the Lomb-Scargle periodogram, to our data (from SuperAGILE) and to the simultaneous data in soft X-rays (from RXTE/ASM). We conclude our investigation with a search for emission in the energy range above 100 MeV with the maximum likelihood technique. In the hard X-ray band the flux of Cyg X-1 shows its typical erratic fluctuations at all timescales with variations of about a factor of two that do not affect significantly the shape of the energy spectrum. From the first order structure function we find that the X-ray emission of Cyg X-1 is characterized by \textit{antipersistence}, indication of a negative feedback mechanism at work. In the gamma ray data a statistically significant point-like source at the position of Cyg X-1 is not found and the upper limit on the flux is $\mathrm{5 \times 10^{-8} \; ph \; cm^{-2} \; s^{-1}}$, over the whole observation (160 days). Finally we compare our upper limit in gamma rays with the expectation of various models of the Cyg X-1 emission, of both hadronic and leptonic origin, in the GeV -- TeV band. The time history of Cyg X-1 in the hard X-ray band over 13 months (not continuous) is shown. Different tools of analysis do not provide fully converging results of the characteristic timescales in the system, suggesting that the timescales found in the structure function are not intrinsic to the physics of the source., Comment: 15 pages and 11 figures (with subfigures). Accepted for publication by A&A.

Published
2010

12. TEMPORAL PROPERTIES OF GX 301-2 OVER A YEAR-LONG OBSERVATION WITH SuperAGILE

Author

A. Pellizzoni, F. Fuschino, L. A. Antonelli, A. W. Chen, S. Cutini, Paolo Soffitta, G. Pucella, Marco Feroci, Luigi Pacciani, F. Perotti, P. Santolamazza, M. Prest, E. Striani, M. Galli, A. Argan, Piergiorgio Picozza, Paolo Lipari, Francesco Lazzarotto, I. Lapshov, Andrea Bulgarelli, F. Verrecchia, Filippo D'Ammando, Enrico Costa, Marco Tavani, G. Di Cocco, G. Piano, S. Sabatini, Massimo Rapisarda, Paolo Giommi, A. Morselli, Francesco Longo, Sandro Mereghetti, F. Boffelli, P. W. Cattaneo, Y. Evangelista, A. Giuliani, Guido Barbiellini, E. Del Monte, Martino Marisaldi, S. Vercellone, L. Salotti, A. Zambra, I. Donnarumma, P. A. Caraveo, Claudio Labanti, Elena Moretti, A. Rappoldi, E. Vallazza, Fulvio Gianotti, V. Vittorini, M. Trifoglio, Maura Pilia, Alessio Trois, B. Preger, C. Pittori, Y., Evangelista, M., Feroci, E., Costa, E. D., Monte, I., Donnarumma, I., Lapshov, F., Lazzarotto, L., Pacciani, M., Rapisarda, P., Soffitta, A., Argan, G., Barbiellini, F., Boffelli, A., Bulgarelli, P., Caraveo, P. W., Cattaneo, A., Chen, F., D'Ammando, G. D., Cocco, F., Fuschino, M., Galli, F., Gianotti, A., Giuliani, C., Labanti, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, G., Pucella, A., Rappoldi, S., Sabatini, E., Striani, M., Tavani, M., Trifoglio, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, L. A., Antonelli, S., Cutini, C., Pittori, B., Preger, P., Santolamazza, F., Verrecchia, P., Giommi, L., Salotti, Evangelista Y, Feroci M, Costa E, Del Monte E, Donnarumma I, Lapshov I, Lazzarotto F, Pacciani L, Rapisarda M, Soffitta P, Argan A, Barbiellini G, Boffelli F, Bulgarelli A, Caraveo P, Cattaneo PW, Chen A, DAmmando F, Di Cocco G, Fuschino F, Galli M, Gianotti F, Giuliani A, Labanti C, Lipari P, Longo F, Marisaldi M, Mereghetti S, Moretti E, Morselli A, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Prest M, Pucella G, Rappoldi A, Sabatini S, Striani E, Tavani M, Trifoglio M, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Antonelli LA, Cutini S, Pittori C, Preger B, Santolamazza P, Verrecchia F, Giommi P, and Salotti L

Subjects
Agile, SuperAGILE, Astrophysics::High Energy Astrophysical Phenomena, Phase (waves), Flux, FOS: Physical sciences, X-ray binary GX 301-2, pulsar, Astrophysics, High Mass X-ray Binaries, High Energy Gamma-ray Astronomy, law.invention, stars: neutron, X-rays: binaries, Pulsar, law, pulsars: individual (GX 3012), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Accretion (meteorology), Astronomy and Astrophysics, AGILE satellite, Light curve, Orbital period, Secular variation, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena, Flare
Abstract

We present the long-term monitoring of the High Mass X-ray Binary GX 301-2 performed with the SuperAGILE instrument on-board the AGILE mission. The source was monitored in the 20-60 keV energy band during the first year of the mission from 2007 July 17 to 2008 August 31, covering about one whole orbital period and three more pre-periastron passages for a total net observation time of about 3.7 Ms. The SuperAGILE dataset represents one of the most continuous and complete monitoring at hard X-ray energies of the 41.5 day long binary period available to date. The source behavior was characterized at all orbital phases in terms of hard X-ray flux, spectral hardness, spin period history, pulsed fraction and pulse shape profile. We also complemented the SuperAGILE observations with the soft X-ray data of the RossiXTE/ASM. Our analysis shows a clear orbital modulation of the spectral hardness, with peaks in correspondence with the pre-periastron flare and near phase 0.25. The hardness peaks we found could be related with the wind-plus-stream accretion model proposed in order to explain the orbital light curve modulation of GX 301-2. Timing analysis of the pulsar spin period shows that the secular trend of the about 680 s pulse period is consistent with the previous observations, although there is evidence of a slight decrease in the spin-down rate. The analysis of the hard X-ray pulsed emission also showed a variable pulse shape profile as a function of the orbital phase, with substructures detected near the passage at the periastron, and a clear modulation of the pulsed fraction, which appears in turn strongly anti-correlated with the source intensity., 10 pages, 7 figures, 3 tables, accepted for publication in ApJ

Published
2010

13. AGILE detection of intense gamma-ray activity from the blazar PKS 0537-441 in October 2008

Author

Marco Feroci, Luigi Pacciani, F. Boffelli, G. De Paris, E. Vallazza, Martino Marisaldi, Claudio Labanti, C. Pittori, T. Froysland, Domenico Impiombato, Ennio Morelli, A. Zambra, A. Morselli, F. Longo, A. Treves, Fulvio Gianotti, A. W. Chen, P. Caraveo, M. Fiorini, L. Salotti, G. Di Cocco, Francesco Lazzarotto, F. Perotti, E. Del Monte, G. Pucella, M. Perri, Filippo D'Ammando, G. Barbiellini, V. Vittorini, M. Prest, P. Santolamazza, M. Galli, G. Piano, F. Verrecchia, Marco Tavani, P. Giommi, P. W. Cattaneo, A. Argan, I. Donnarumma, Y. Evangelista, Andrea Bulgarelli, A. Pellizzoni, Sandro Mereghetti, Enrico Costa, Maura Pilia, Elena Pian, E. Striani, Alessio Trois, P. Picozza, I. Lapshov, S. Colafrancesco, M. Trifoglio, S. Sabatini, A. Giuliani, D. Zanello, Hans A. Krimm, Massimo Rapisarda, L. A. Antonelli, V. Cocco, A. Rappoldi, Paolo Lipari, F. Fuschino, D. Fugazza, Paolo Soffitta, P. Romano, S. Vercellone, Pucella G, DAmmando F, Romano P, Treves A, Pian E, Vercellone S, Vittorini V, Piano G, Impiombato D, Fugazza D, Verrecchia F, Krimm HA, Donnarumma I, Tavani M, Bulgarelli A, Chen AW, Giuliani A, Longo F, Pacciani L, Argan A, Barbiellini G, Boffelli F, Caraveo P, Cattaneo PW, Cocco V, Costa E, Del Monte E, De Paris G, Di Cocco G, Evangelista Y, Feroci M, Fiorini M, Froysland T, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Marisaldi M, Mereghetti S, Morelli E, Morselli A, Pellizzoni A, Perotti F, Picozza P, Pilia M, Prest M, Rapisarda M, Rappoldi A, Sabatini S, Soffitta P, Striani E, Trifoglio M, Trois A, Vallazza E, Zambra A, Zanello D, Perri M, Pittori C, Santolamazza P, Giommi P, Antonelli LA, Colafrancesco S, Salotti L, G., Pucella, F., D'Ammando, P., Romano, A., Treve, E., Pian, S., Vercellone, V., Vittorini, G., Piano, D., Impiombato, D., Fugazza, F., Verrecchia, H. A., Krimm, I., Donnarumma, M., Tavani, A., Bulgarelli, A. W., Chen, A., Giuliani, Longo, Francesco, L., Pacciani, A., Argan, G., Barbiellini, F., Boffelli, P., Caraveo, P. W., Cattaneo, V., Cocco, E., Costa, E. D., Monte, G. D., Pari, G. D., Cocco, Y., Evangelista, M., Feroci, M., Fiorini, T., Froysland, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, S., Mereghetti, E., Morelli, A., Morselli, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, S., Sabatini, P., Soffitta, E., Striani, M., Trifoglio, A., Troi, E., Vallazza, A., Zambra, D., Zanello, M., Perri, C., Pittori, P., Santolamazza, P., Giommi, L. A., Antonelli, S., Colafrancesco, and L., Salotti

Subjects
Swift Gamma-Ray Burst Mission, gamma-ray activity, Astrophysics::High Energy Astrophysical Phenomena, Flux, Context (language use), Astrophysics, High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, law.invention, Luminosity, Telescope, AGILE, X-ray, law, Target of opportunity, gamma rays: general – BL Lacertae objects: individual: PKS 0537-441 – radiation mechanisms: non-thermal, Blazar, Physics, Astronomy, Astronomy and Astrophysics, Gamma-Ray Imaging Detector, Space and Planetary Science, Spectral energy distribution
Abstract

Context. We report the detection by the AGILE satellite of intense gamma-ray activity from the source 1AGL J0538-4424, associated with the low-energy-peaked BL Lac PKS 0537-441, during a target of opportunity (ToO) observation performed on 2008 October 10-17, triggered by a Fermi-LAT alert, together with REM and Swift observations. Aims. The quasi-simultaneous near-infrared, optical, UV, X-ray, and gamma-ray coverage allowed us to investigate the behaviour of the source in different energy bands and study the spectral energy distribution and a theoretical model that can describe the gamma-ray state observed in mid-October. Methods. AGILE observed the source with its two co-aligned imagers: the Gamma-Ray Imaging Detector (GRID) and the hard X-ray imager (SuperAGILE), sensitive in the 30 MeV-30 GeV and 18-60 keV ranges, respectively. During the AGILE observation, the source was monitored simultaneously in the UV and X-ray bands by the Swift satellite through 6 ToO observations carried out between 2008 October 8 and 17. Moreover, the source was observed in the near-infrared and optical bands by the REM telescope on 2008 October 7, 8, and 9. Results. During 2008 October 10-17, AGILE-GRID detected gamma-ray emission from PKS 0537-441 at a significance level of 5.3-sigma with an average flux of (42 +/- 11) x 10(-8) photons cm(-2) s(-1) for energies higher than 100 MeV. A significant increase in the gamma-ray activity was detected between the first and the second halves of the observing period. REM and Swift/XRT detected the source in near-infrared/optical and X-rays during a relatively low and intermediate activity state, respectively, with no signs of evident variability in the different observations. However, Swift/UVOT detected an increase between the first and the second parts of the observing period, smaller than in the gamma-rays. Conclusions. The average gamma-ray flux of PKS 0537-441 detected by AGILE is close to the average flux observed for this source by the EGRET and Fermi-LAT instruments, with an increase of a factor 3 throughout the observation period up to a flux level slightly lower than the highest flux observed by Fermi-LAT during the first 11 months of operation. The spectral energy distribution of PKS 0537-441 in mid-October 2008 seems to require two synchrotron self-Compton components to be modelled, to account for both the near-infrared/optical bump and the X-ray data, together with the information on the gamma-ray flux level observed by AGILE. An alternative model based on the external Compton radiation, which requires an accretion disk with a relatively high luminosity, is also proposed.

Published
2010

14. The Extraordinary Gamma-Ray Flare Of The Blazar 3c 454.3

Author

E. Striani, S. Vercellone, M. Tavani, V. Vittorini, F. D’Ammando, I. Donnarumma, L. Pacciani, G. Pucella, A. Bulgarelli, M. Trifoglio, F. Gianotti, P. Giommi, A. Argan, G. Barbiellini, P. Caraveo, P. W. Cattaneo, A. W. Chen, E. Costa, G. De Paris, E. Del Monte, G. Di Cocco, Y. Evangelista, M. Feroci, A. Ferrari, M. Fiorini, F. Fuschino, M. Galli, A. Giuliani, M. Giusti, C. Labanti, F. Lazzarotto, P. Lipari, F. Longo, M. Marisaldi, S. Mereghetti, E. Morelli, E. Moretti, A. Morselli, A. Pellizzoni, F. Perotti, G. Piano, P. Picozza, M. Pilia, M. Prest, M. Rapisarda, A. Rappoldi, S. Sabatini, E. Scalise, P. Soffitta, A. Trois, E. Vallazza, A. Zambra, D. Zanello, C. Pittori, F. Verrecchia, P. Santolamazza, F. Lucarelli, S. Colafrancesco, L. A. Antonelli, L. Salotti, E., Striani, S., Vercellone, M., Tavani, V., Vittorini, F., D'Ammando, I., Donnarumma, L., Pacciani, G., Pucella, A., Bulgarelli, M., Trifoglio, F., Gianotti, P., Giommi, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, A. W., Chen, E., Costa, G. D., Pari, E. D., Monte, G. D., Cocco, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, F., Fuschino, M., Galli, A., Giuliani, M., Giusti, C., Labanti, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, S., Sabatini, E., Scalise, P., Soffitta, A., Troi, E., Vallazza, A., Zambra, D., Zanello, C., Pittori, F., Verrecchia, P., Santolamazza, F., Lucarelli, S., Colafrancesco, L. A., Antonelli, L., Salotti, Striani E, Vercellone S, Tavani M, Vittorini V, DAmmando F, Donnarumma I, Pacciani L, Pucella G, Bulgarelli A, Trifoglio M, Gianotti F, Giommi P, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, Chen AW, Costa E, De Paris G, Del Monte E, Di Cocco G, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Fuschino F, Galli M, Giuliani A, Giusti M, Labanti C, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Prest M, Rapisarda M, Rappoldi A, Sabatini S, Scalise E, Soffitta P, Trois A, Vallazza E, Zambra A, Zanello D, Pittori C, Verrecchia F, Santolamazza P, Lucarelli F, Colafrancesco S, Antonelli LA, and Salotti L

Subjects
Agile, Cosmology and Nongalactic Astrophysics (astro-ph.CO), blazar, gamma detection, Astrophysics::High Energy Astrophysical Phenomena, Flux, FOS: Physical sciences, Astrophysics, Type (model theory), Vela, High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, law.invention, Pulsar, law, Blazar, Physics, gamma rays: galaxies – quasars: individual (3C 454.3), Gamma ray, Astronomy and Astrophysics, Quasar, Space and Planetary Science, Astrophysics - Cosmology and Nongalactic Astrophysics, Flare
Abstract

We present the gamma-ray data of the extraordinary flaring activity above 100 MeV from the flat spectrum radio quasar 3C 454.3 detected by AGILE during the month of December 2009. 3C 454.3, that has been among the most active blazars of the FSRQ type since 2007, was detected in the gamma-ray range with a progressively rising flux since November 10, 2009. The gamma-ray flux reached a value comparable with that of the Vela pulsar on December 2, 2009. Remarkably, between December 2 and 3, 2009 the source more than doubled its gamma-ray emission and became the brightest gamma-ray source in the sky with a peak flux of F_{\gamma,p} = (2000 \pm 400) x 10^-8 ph cm^-2 s^-1 for a 1-day integration above 100 MeV. The gamma-ray intensity decreased in the following days with the source flux remaining at large values near F \simeq (1000 \pm 200) x 10^-8 ph cm^-2 s^-1 for more than a week. This exceptional gamma-ray flare dissipated among the largest ever detected intrinsic radiated power in gamma-rays above 100 MeV (L_{\gamma, source, peak} \simeq 3 x 10^46 erg s^-1, for a relativistic Doppler factor of {\delta} \simeq 30). The total isotropic irradiated energy of the month-long episode in the range 100 MeV - 3 GeV is E_{\gamma,iso} \simeq 10^56 erg. We report the intensity and spectral evolution of the gamma-ray emission across the flaring episode. We briefly discuss the important theoretical implications of our detection., Comment: 17 pages, 3 figures, ApJ accepted

Published
2010

15. Episodic Transient Gamma-Ray Emission From The Microquasar Cygnus X-1

Author

E. Moretti, V. Vittorini, Claudio Labanti, A. Giuliani, M. Trifoglio, C. Pittori, Francesco Lazzarotto, Paolo Lipari, Martino Marisaldi, Attilio Ferrari, Guido Barbiellini, P. Santolamazza, A. Pellizzoni, F. Perotti, S. Vercellone, M. Galli, Piergiorgio Picozza, E. Striani, Y. Evangelista, M. Giusti, Francesco Longo, Alda Rubini, F. Verrecchia, Ennio Morelli, Paolo Giommi, G. De Paris, Massimiliano Fiorini, Marco Tavani, F. Fuschino, G. Di Cocco, A. Rappoldi, E. Vallazza, S. Sabatini, Sergio Colafrancesco, Fulvio Gianotti, A. Argan, Sandro Mereghetti, P. W. Cattaneo, Andrea Bulgarelli, A. Morselli, I. Donnarumma, Enrico Costa, Filippo D'Ammando, Marco Feroci, Luigi Pacciani, M. Prest, Paolo Soffitta, L. A. Antonelli, A. W. Chen, E. Del Monte, Massimo Rapisarda, G. Piano, P. A. Caraveo, Maura Pilia, D. Zanello, G. Pucella, Alessio Trois, E. Scalise, L. Salotti, A. Zambra, F. de Pasquale, Sabatini S, Tavani M, Striani E, Bulgarelli A, Vittorini V, Piano G, Del Monte E, Feroci M, de Pasquale F, Trifoglio M, Gianotti F, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, Chen AW, DAmmando F, Costa E, De Paris G, Di Cocco G, Donnarumma I, Evangelista Y, Ferrari A, Fiorini M, Fuschino F, Galli M, Giuliani A, Giusti M, Labanti C, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Pilia M, Pucella G, Prest M, Rapisarda M, Rappoldi A, Rubini A, Scalise E, Soffitta P, Trois A, Vallazza E, Vercellone S, Zambra A, Zanello D, Pittori C, Verrecchia F, Santolamazza P, Giommi P, Colafrancesco S, Antonelli LA, Salotti L, S., Sabatini, M., Tavani, E., Striani, A., Bulgarelli, V., Vittorini, G., Piano, E. D., Monte, M., Feroci, F. d., Pasquale, M., Trifoglio, F., Gianotti, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, A. W., Chen, F., D'Ammando, E., Costa, G. D., Pari, G. D., Cocco, I., Donnarumma, Y., Evangelista, A., Ferrari, M., Fiorini, F., Fuschino, M., Galli, A., Giuliani, M., Giusti, C., Labanti, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, G., Pucella, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, E., Scalise, P., Soffitta, A., Troi, E., Vallazza, S., Vercellone, A., Zambra, D., Zanello, C., Pittori, F., Verrecchia, P., Santolamazza, P., Giommi, S., Colafrancesco, L. A., Antonelli, and L., Salotti

Subjects
Agile, Black Holes, transient gamma-ray emission, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Flux, Astrophysics, High Energy Gamma-ray Astronomy, X-rays: binaries, Cutoff, Cygnus X-1, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Range (particle radiation), Gamma ray, Astronomy and Astrophysics, gamma rays: general, stars: individual (Cygnus X-1), Galaxy, Black hole, Space and Planetary Science, AGILE satellite, Transient (oscillation), Astrophysics - High Energy Astrophysical Phenomena, Energy (signal processing)
Abstract

Cygnus X-1 is the archetypal black hole (BH) binary system in our Galaxy. We report the main results of an extensive search for transient gamma-ray emission from Cygnus X-1 carried out in the energy range 100 MeV - 3 GeV by the AGILE satellite, during the period 2007 July - 2009 October. The total exposure time is about 300 days, during which the source was in the "hard" X-ray spectral state. We divided the observing intervals in 2 or 4 week periods, and searched for transient and persistent emission. We report an episode of significant transient gamma-ray emission detected on 2009, October 16 in a position compatible with Cygnus X-1 optical position. This episode, occurred during a hard spectral state of Cygnus X-1, shows that a 1-2 day time variable emission above 100 MeV can be produced during hard spectral states, having important theoretical implications for current Comptonization models for Cygnus X-1 and other microquasars. Except for this one short timescale episode, no significant gamma-ray emission was detected by AGILE. By integrating all available data we obtain a 2$\sigma$ upper limit for the total integrated flux of $F_{\gamma,U.L.} = 3 \times 10^{-8} \rm ph cm^{-2} s^{-1}$ in the energy range 100 MeV - 3 GeV. We then clearly establish the existence of a spectral cutoff in the energy range 1-100 MeV that applies to the typical hard state outside the flaring period and that confirms the historically known spectral cutoff above 1 MeV., Comment: Accepted for publication by ApJ on the 9th of Feb 2010, 5 pages, 3 figures

Published
2010

16. Extreme particle acceleration in the microquasar Cygnus X-3

Author

Francesco Longo, Martino Marisaldi, C. Pittori, Paolo Lipari, Arnaud Ferrari, M. Prest, Sandro Mereghetti, P. W. Cattaneo, S. Sabatini, A. Pellizzoni, E. Striani, I. Lapshov, F. Perotti, S. Colafrancesco, Fulvio Gianotti, Francesco Lazzarotto, A. Giuliani, E. Rossi, Ennio Morelli, Karri I. I. Koljonen, Marco Tavani, E. Scalise, Y. Evangelista, Maura Pilia, Guy G. Pooley, M. Galli, F. Fuschino, Alessio Trois, I. Donnarumma, Massimo Rapisarda, F. Verrecchia, N. A. Nizhelskij, P. A. Caraveo, E. Del Monte, D. Zanello, L. Salotti, V. Cocco, M. Trifoglio, G. Pucella, A. Mauri, A. Rappoldi, E. Vallazza, G. De Paris, T. Contessi, G. Piano, A. W. Chen, P. Giommi, A. Argan, Andrea Bulgarelli, Enrico Costa, G. Di Persio, A. Morselli, Filippo D'Ammando, Paolo Soffitta, S. Vercellone, Michael L. McCollough, P. Picozza, P. Santolamazza, Alda Rubini, Sergei A. Trushkin, A. Zambra, M. Mastropietro, Guido Barbiellini, V. Vittorini, Marco Feroci, Luigi Pacciani, Angelo Antonelli, E. Mattaini, G. Di Cocco, Claudio Labanti, M., Tavani, A., Bulgarelli, G., Piano, S., Sabatini, E., Striani, Y., Evangelista, A., Troi, G., Pooley, S., Trushkin, N. A., Nizhelskij, M., Mccollough, K. I. I., Koljonen, G., Pucella, A., Giuliani, A. W., Chen, E., Costa, V., Vittorini, M., Trifoglio, F., Gianotti, A., Argan, G., Barbiellini, P., Caraveo, P. W., Cattaneo, V., Cocco, T., Contessi, F., D'Ammando, E. D., Monte, G. D., Pari, G. D., Cocco, G. D., Persio, I., Donnarumma, M., Feroci, A., Ferrari, F., Fuschino, M., Galli, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, E., Mattaini, M., Marisaldi, M., Mastropietro, A., Mauri, S., Mereghetti, E., Morelli, A., Morselli, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, M., Prest, M., Rapisarda, A., Rappoldi, E., Rossi, A., Rubini, E., Scalise, P., Soffitta, E., Vallazza, S., Vercellone, A., Zambra, D., Zanello, C., Pittori, F., Verrecchia, P., Giommi, S., Colafrancesco, P., Santolamazza, A., Antonelli, L., Salotti, Tavani M, Bulgarelli A, Piano G, Sabatini S, Striani E, Evangelista Y, Trois A, Pooley G, Trushkin S, Nizhelskij NA, McCollough M, Koljonen KII, Pucella G, Giuliani A, Chen AW, Costa E, Vittorini V, Trifoglio M, Gianotti F, Argan A, Barbiellini G, Caraveo P, Cattaneo PW, Cocco V, Contessi T, DAmmando F, Del Monte E, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Feroci M, Ferrari A, Fuschino F, Galli M, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Longo F, Mattaini E, Marisaldi M, Mastropietro M, Mauri A, Mereghetti S, Morelli E, Morselli A, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Pilia M, Prest M, Rapisarda M, Rappoldi A, Rossi E, Rubini A, Scalise E, Soffitta P, Vallazza E, Vercellone S, Zambra A, Zanello D, Pittori C, Verrecchia F, Giommi P, Colafrancesco S, Santolamazza P, Antonelli A, and Salotti L

Subjects
Active galactic nucleus, Black Holes, Astrophysics::High Energy Astrophysical Phenomena, super massive black holes, X-ray binary, Astrophysics::Cosmology and Extragalactic Astrophysics, Astrophysics, High Energy Gamma-ray Astronomy, Relativistic particle, AGILE, Astrophysical jet, Astrophysics::Solar and Stellar Astrophysics, Astrophysics::Galaxy Astrophysics, Physics, Supermassive black hole, Cygnus, Multidisciplinary, particle acceleration, microquasar, Cygnus X-3, Astronomy, X-ray emission, Particle acceleration, Black hole, Neutron star, AGILE satellite
Abstract

Galactic microquasars are binaries with a neutron star or stellar-mass black hole accreting gas from a companion star. They can accelerate particles to relativistic energies and emit radio flares, but the mechanism of jet energization is not known. A survey of the Cygnus region between mid-2007 and mid-2009 has detected four major γ-ray flaring episodes with energies over 100 MeV, each lasting 1 or 2 days, emanating from the microquasar Cygnus X-3. There is a clear pattern of temporal correlation between the γ-ray flares and transitional spectral states of radio and X-ray emission. Particle acceleration occurred a few days before radio jet ejections for two of the flares, suggesting that jet formation involves the production of highly energetic particles. Super-massive black holes in active galaxies can accelerate particles to relativistic energies, producing jets with associated γ-ray emission. Galactic 'microquasars' also produce relativistic jets; however, apart from an isolated event detected in Cygnus X-1, there has hitherto been no systematic evidence for the acceleration of particles to gigaelectronvolt or higher energies in a microquasar. Here, a report of four γ-ray flares with energies above 100 MeV from the microquasar Cygnus X-3 illuminates this important problem. Super-massive black holes in active galaxies can accelerate particles to relativistic energies1, producing jets with associated γ-ray emission. Galactic ‘microquasars’, which are binary systems consisting of a neutron star or stellar-mass black hole accreting gas from a companion star, also produce relativistic jets, generally together with radio flares2. Apart from an isolated event detected3 in Cygnus X-1, there has hitherto been no systematic evidence for the acceleration of particles to gigaelectronvolt or higher energies in a microquasar, with the consequence that we are as yet unsure about the mechanism of jet energization. Here we report four γ-ray flares with energies above 100 MeV from the microquasar Cygnus X-3 (an exceptional X-ray binary4,5,6 that sporadically produces radio jets7,8,9). There is a clear pattern of temporal correlations between the γ-ray flares and transitional spectral states of the radio-frequency and X-ray emission. Particle acceleration occurred a few days before radio-jet ejections for two of the four flares, meaning that the process of jet formation implies the production of very energetic particles. In Cygnus X-3, particle energies during the flares can be thousands of times higher than during quiescent states.

Published
2009

17. First AGILE catalog of high-confidence gamma-ray sources

Author

Dario Gasparrini, I. Donnarumma, F. Mauri, E. Scalise, E. Mattaini, G. Di Cocco, E. Del Monte, E. Rossi, Geiland Porrovecchio, Fulvio Gianotti, F. Fornari, A. Morselli, G. De Paris, Marco Feroci, Luigi Pacciani, G. Di Persio, S. Cutini, A. W. Chen, Sandro Mereghetti, F. Boffelli, P. W. Cattaneo, S. Stellato, Francesco Longo, Massimo Rapisarda, R. Primavera, A. Antonelli, Filippo D'Ammando, M. Galli, Piergiorgio Picozza, F. Tamburelli, C. Pittori, L. Salotti, Paolo Soffitta, F. Verrecchia, A. Zambra, T. Froysland, B. Preger, P. Santolamazza, D. Zanello, V. Vittorini, G. Fanari, F. Fuschino, F. Perotti, Martino Marisaldi, A. Pellizzoni, Marcello Mastropietro, Francesco Lazzarotto, M. Trifoglio, A. Argan, Massimo Frutti, Andrea Bulgarelli, Maura Pilia, P. A. Caraveo, Enrico Costa, Alessio Trois, F. Liello, Claudio Labanti, Alda Rubini, E. Striani, Marco Tavani, S. Vercellone, S. Sabatini, Sergio Colafrancesco, I. Lapshov, Paolo Giommi, Ennio Morelli, M. Prest, Massimiliano Fiorini, P. Lipari, Attilio Ferrari, Guido Barbiellini, Elena Moretti, G. Pucella, A. Mauri, A. Rappoldi, E. Vallazza, Alessandro Traci, V. Cocco, A. Giuliani, Y. Evangelista, T. Contessi, G. Piano, C. Pontoni, C., Pittori, F., Verrecchia, A. W., Chen, A., Bulgarelli, A., Pellizzoni, A., Giuliani, S., Vercellone, Longo, Francesco, M., Tavani, P., Giommi, G., Barbiellini, M., Trifoglio, F., Gianotti, A., Argan, A., Antonelli, F., Boffelli, P., Caraveo, P. W., Cattaneo, V., Cocco, S., Colafrancesco, T., Contessi, E., Costa, S., Cutini, F., D'Ammando, E. D., Monte, G. D., Pari, G. D., Cocco, G. D., Persio, I., Donnarumma, Y., Evangelista, G., Fanari, M., Feroci, A., Ferrari, M., Fiorini, F., Fornari, F., Fuschino, T., Froysland, M., Frutti, M., Galli, D., Gasparrini, C., Labanti, I., Lapshov, F., Lazzarotto, F., Liello, P., Lipari, E., Mattaini, M., Marisaldi, M., Mastropietro, A., Mauri, F., Mauri, S., Mereghetti, E., Morelli, Moretti, Elena, A., Morselli, L., Pacciani, F., Perotti, G., Piano, P., Picozza, M., Pilia, C., Pontoni, G., Porrovecchio, B., Preger, M., Prest, R., Primavera, G., Pucella, M., Rapisarda, A., Rappoldi, E., Rossi, A., Rubini, S., Sabatini, P., Santolamazza, E., Scalise, P., Soffitta, S., Stellato, E., Striani, F., Tamburelli, A., Traci, A., Troi, E., Vallazza, V., Vittorini, A., Zambra, D., Zanello, L., Salotti, Pittori C, Verrecchia F, Chen AW, Bulgarelli A, Pellizzoni A, Giuliani A, Vercellone S, Longo F, Tavani M, Giommi P, Barbiellini G, Trifoglio M, Gianotti F, Argan A, Antonelli A, Boffelli F, Caraveo P, Cattaneo PW, Cocco V, Colafrancesco S, Contessi T, Costa E, Cutini S, DAmmando F, Del Monte E, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Fanari G, Feroci M, Ferrari A, Fiorini M, Fornari F, Fuschino F, Froysland T, Frutti M, Galli M, Gasparrini D, Labanti C, Lapshov I, Lazzarotto F, Liello F, Lipari P, Mattaini E, Marisaldi M, Mastropietro M, Mauri A, Mauri F, Mereghetti S, Morelli E, Moretti E, Morselli A, Pacciani L, Perotti F, Piano G, Picozza P, Pilia M, Pontoni C, Porrovecchio G, Preger B, Prest M, Primavera R, Pucella G, Rapisarda M, Rappoldi A, Rossi E, Rubini A, Sabatini S, Santolamazza P, Scalise E, Soffitta P, Stellato S, Striani E, Tamburelli F, Traci A, Trois A, Vallazza E, Vittorini V, Zambra A, Zanello D, and Salotti L

Subjects
Agile, catalog, media_common.quotation_subject, Astrophysics::High Energy Astrophysical Phenomena, FOS: Physical sciences, Field of view, Astrophysics, gamma-ray source, High Energy Gamma-ray Astronomy, Pulsar, X and gamma detection, Blazar, media_common, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), Detector, Gamma ray, gamma rays: observations, catalogs, Astronomy and Astrophysics, Radius, AGILE satellite, Catalogs, Space and Planetary Science, Sky, Satellite, Astrophysics - High Energy Astrophysical Phenomena
Abstract

We present the first catalog of high-confidence gamma-ray sources detected by the AGILE satellite during observations performed from July 9, 2007 to June 30, 2008. Catalogued sources are detected by merging all the available data over the entire time period. AGILE, launched in April 2007, is an ASI mission devoted to gamma-ray observations in the 30 MeV - 50 GeV energy range, with simultaneous X-ray imaging capability in the 18-60 keV band. This catalog is based on Gamma-Ray Imaging Detector (GRID) data for energies greater than 100 MeV. For the first AGILE catalog we adopted a conservative analysis, with a high-quality event filter optimized to select gamma-ray events within the central zone of the instrument Field of View (radius of 40 degrees). This is a significance-limited (4 sigma) catalog, and it is not a complete flux-limited sample due to the non-uniform first year AGILE sky coverage. The catalog includes 47 sources, 21 of which are associated with confirmed or candidate pulsars, 13 with Blazars (7 FSRQ, 4 BL Lacs, 2 unknown type), 2 with HMXRBs, 2 with SNRs, 1 with a colliding-wind binary system, 8 with unidentified sources., Revised version, 15 pages, 3 figures, 3 tables. To be published in Astronomy and Astrophysics. Text improved and clarified. Refined analysis of complex regions of the Galactic plane yields a new list of high-confidence sources including 47 sources (compared with the 40 sources appearing in the first version)

Published
2009

18. Multiwavelength Observations Of 3c 454.3. Ii. The Agile 2007 December Campaign

Author

I. Donnarumma, G. Pucella, V. Vittorini, F. D'Ammando, S. Vercellone, C. M. Raiteri, M. Villata, M. Perri, W. P. Chen, R. L. Smart, J. Kataoka, N. Kawai, Y. Mori, G. Tosti, D. Impiombato, T. Takahashi, R. Sato, M. Tavani, A. Bulgarelli, A. W. Chen, A. Giuliani, F. Longo, L. Pacciani, A. Argan, G. Barbiellini, F. Boffelli, P. Caraveo, P. W. Cattaneo, V. Cocco, T. Contessi, E. Costa, E. Del Monte, G. De Paris, G. Di Cocco, Y. Evangelista, M. Feroci, A. Ferrari, M. Fiorini, T. Froysland, M. Frutti, F. Fuschino, M. Galli, F. Gianotti, C. Labanti, I. Lapshov, F. Lazzarotto, P. Lipari, M. Marisaldi, M. Mastropietro, S. Mereghetti, E. Morelli, E. Moretti, A. Morselli, A. Pellizzoni, F. Perotti, G. Piano, P. Picozza, M. Pilia, G. Porrovecchio, M. Prest, M. Rapisarda, A. Rappoldi, A. Rubini, S. Sabatini, E. Scalise, P. Soffitta, E. Striani, M. Trifoglio, A. Trois, E. Vallazza, A. Zambra, D. Zanello, C. Pittori, P. Santolamazza, F. Verrecchia, P. Giommi, L. A. Antonelli, S. Colafrancesco, L. Salotti, Donnarumma I, Pucella G, Vittorini V, DAmmando F, Vercellone S, Raiteri CM, Villata M, Perri M, Chen WP, Smart RL, Kataoka J, Kawai N, Mori Y, Tosti G, Impiombato D, Takahashi T, Sato R, Tavani M, Bulgarelli A, Chen AW, Giuliani A, Longo F, Pacciani L, Argan A, Barbiellini G, Boffelli F, Caraveo P, Cattaneo PW, Cocco V, Contessi T, Costa E, Del Monte E, De Paris G, Di Cocco G, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Froysland T, Frutti M, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Marisaldi M, Mastropietro M, Mereghetti S, Morelli E, Moretti E, Morselli A, Pellizzoni A, Perotti F, Piano G, Picozza P, Pilia M, Porrovecchio G, Prest M, Rapisarda M, Rappoldi A, Rubini A, Sabatini S, Scalise E, Soffitta P, Striani E, Trifoglio M, Trois A, Vallazza E, Zambra A, Zanello D, Pittori C, Santolamazza P, Verrecchia F, Giommi P, Antonelli A, Colafrancesco S, Salotti L, I., Donnarumma, G., Pucella, V., Vittorini, F., D'Ammando, S., Vercellone, C. M., Raiteri, M., Villata, M., Perri, W. P., Chen, R. L., Smart, J., Kataoka, N., Kawai, Y., Mori, G., Tosti, D., Impiombato, T., Takahashi, R., Sato, M., Tavani, A., Bulgarelli, A. W., Chen, A., Giuliani, Longo, Francesco, L., Pacciani, A., Argan, G., Barbiellini, F., Boffelli, P., Caraveo, P. W., Cattaneo, V., Cocco, T., Contessi, E., Costa, E. D., Monte, G. D., Pari, G. D., Cocco, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, T., Froysland, M., Frutti, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, M., Marisaldi, M., Mastropietro, S., Mereghetti, E., Morelli, E., Moretti, A., Morselli, A., Pellizzoni, F., Perotti, G., Piano, P., Picozza, M., Pilia, G., Porrovecchio, M., Prest, M., Rapisarda, A., Rappoldi, A., Rubini, S., Sabatini, E., Scalise, P., Soffitta, E., Striani, M., Trifoglio, A., Troi, E., Vallazza, A., Zambra, D., Zanello, C., Pittori, P., Santolamazza, F., Verrecchia, P., Giommi, A., Antonelli, S., Colafrancesco, and L., Salotti

Subjects
Agile, Photon, Cosmology and Nongalactic Astrophysics (astro-ph.CO), Astrophysics::High Energy Astrophysical Phenomena, galaxies: active, Flux, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, High Energy Gamma-ray Astronomy, AGILE satellite, Active Galactic Nuclei, blazar, law.invention, law, Target of opportunity, quasars: general, multiwavelength campaign, Blazar, Astrophysics::Galaxy Astrophysics, Line (formation), Physics, High Energy Astrophysical Phenomena (astro-ph.HE), We report on the second Astrorivelatore Gamma a Immagini Leggero (AGILE) multiwavelength campaign of the blazar 3C 454.3 during the first half of 2007 December. This campaign involved AGILE, Spitzer, Swift, Suzaku, the Whole Earth Blazar Telescope (WEBT) consortium, the Rapid Eye Mount (REM), and the Multicolor Imaging Telescopes for Survey and Monstrous Explosions (MITSuME) telescopes, offering a broadband coverage that allowed for a simultaneous sampling of the synchrotron and inverse Compton (IC) emissions. The two-week AGILE monitoring was accompanied by radio to optical monitoring by WEBT and REM, and by sparse observations in mid-infrared and soft/hard X-ray energy bands performed by means of Target of Opportunity observations by Spitzer, Swift, and Suzaku, respectively. The source was detected with an average flux of ~250 × 10^-8 photons cm^-2 s^-1 above 100 MeV, typical of its flaring states. The simultaneous optical and γ-ray monitoring allowed us to study the time lag associated with the variability in the two energy bands, resulting in a possible lsimone-day delay of the γ-ray emission with respect to the optical one. From the simultaneous optical and γ-ray fast flare detected on December 12, we can constrain the delay between the γ-ray and optical emissions within 12 hr. Moreover, we obtain three spectral energy distributions (SEDs) with simultaneous data for 2007 December 5, 13, and 15, characterized by the widest multifrequency coverage. We found that a model with an external Compton on seed photons by a standard disk and reprocessed by the broad-line regions does not describe in a satisfactory way the SEDs of 2007 December 5, 13, and 15. An additional contribution, possibly from the hot corona with T = 106 K surrounding the jet, is required to account simultaneously for the softness of the synchrotron and the hardness of the IC emissions during those epochs, Astronomy and Astrophysics, galaxies: jets, radiation mechanisms: non-thermal, Corona, Synchrotron, Space and Planetary Science, galaxies: individual: 3C 454.3, Astrophysics - High Energy Astrophysical Phenomena, gamma rays: observations, Astrophysics - Cosmology and Nongalactic Astrophysics, Flare
Abstract

著者人数：79名, Accepted: 2009-10-29, 資料番号: SA1000754000

Published
2009

19. Detection of Gamma-Ray Emission from the Vela Pulsar Wind Nebula with AGILE

Author

A. Pellizzoni, M. Galli, A. Giuliani, F. Verrecchia, Francesco Lazzarotto, E. Vallazza, C. Pittori, T. Contessi, N. D'Amico, G. Piano, G. De Paris, A. Argan, Sandro Mereghetti, E. Rossi, E. Scalise, A. Morselli, Arnaud Ferrari, E. Striani, P. Santolamazza, Andrea Bulgarelli, F. Fuschino, I. Lapshov, S. Colafrancesco, L. Salotti, I. Donnarumma, Y. Evangelista, Massimo Rapisarda, G. Di Cocco, A. Possenti, Enrico Costa, S. Sabatini, Alda Rubini, P. W. Cattaneo, G. Pucella, P. Picozza, Marco Tavani, G. Barbiellini, Elena Moretti, Martino Marisaldi, A. Rappoldi, D. Zanello, M. Prest, V. Cocco, M. Mastropietro, F. Perotti, M. Burgay, V. Vittorini, A. W. Chen, Claudio Labanti, A. Zambra, Paolo Lipari, P. Giommi, J. Palfreyman, Giovanni F. Bignami, P. A. Caraveo, M. Trifoglio, M. Fiorini, E. Del Monte, Aidan Hotan, F. Longo, Angelo Antonelli, Marco Feroci, Luigi Pacciani, Maura Pilia, Alessio Trois, Paolo Esposito, Fulvio Gianotti, G. Di Persio, Filippo D'Ammando, Paolo Soffitta, S. Vercellone, Pellizzoni A, Trois A, Tavani M, Pilia M, Giuliani A, Pucella G, Esposito P, Sabatini S, Piano G, Argan A, Barbiellini G, Bulgarelli A, Burgay M, Caraveo P, Cattaneo PW, Chen AW, Cocco V, Contessi T, Costa E, DAmmando F, Del Monte E, De Paris G, Di Cocco G, Di Persio G, Donnarumma I, Evangelista Y, Feroci M, Ferrari A, Fiorini M, Fuschino F, Galli M, Gianotti F, Hotan A, Labanti C, Lapshov I, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mastropietro M, Mereghetti S, Moretti E, Morselli A, Pacciani L, Palfreyman J, Perotti F, Picozza P, Pittori C, Possenti A, Prest M, Rapisarda M, Rappoldi A, Rossi E, Rubini A, Santolamazza P, Scalise E, Soffitta P, Striani E, Trifoglio M, Vallazza E, Vercellone S, Verrecchia F, Vittorini V, Zambra A, Zanello D, Giommi P, Colafrancesco S, Antonelli A, Salotti L, D'Amico N, Bignami GF, A., Pellizzoni, A., Troi, M., Tavani, M., Pilia, A., Giuliani, G., Pucella, P., Esposito, S., Sabatini, G., Piano, A., Argan, G., Barbiellini, A., Bulgarelli, M., Burgay, P., Caraveo, P. W., Cattaneo, A. W., Chen, V., Cocco, T., Contessi, E., Costa, F., D'Ammando, E. D., Monte, G. D., Pari, G. D., Cocco, G. D., Persio, I., Donnarumma, Y., Evangelista, M., Feroci, A., Ferrari, M., Fiorini, F., Fuschino, M., Galli, F., Gianotti, A., Hotan, C., Labanti, I., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, M., Mastropietro, S., Mereghetti, E., Moretti, A., Morselli, L., Pacciani, J., Palfreyman, F., Perotti, P., Picozza, C., Pittori, A., Possenti, M., Prest, M., Rapisarda, A., Rappoldi, E., Rossi, A., Rubini, P., Santolamazza, E., Scalise, P., Soffitta, E., Striani, M., Trifoglio, E., Vallazza, S., Vercellone, F., Verrecchia, V., Vittorini, A., Zambra, D., Zanello, P., Giommi, S., Colafrancesco, A., Antonelli, L., Salotti, N., D'Amico, and G. F., Bignami

Subjects
Astrophysics::High Energy Astrophysical Phenomena, Population, FOS: Physical sciences, Astrophysics, Astrophysics::Cosmology and Extragalactic Astrophysics, Vela, Pulsar wind nebula, High Energy Gamma-ray Astronomy, gamma detection, Relativistic particle, AGILE, Pulsar Wind Nebulae, Pulsar, Astrophysics::Solar and Stellar Astrophysics, AGILE satellite, education, Astrophysics::Galaxy Astrophysics, pulsar, Physics, High Energy Astrophysical Phenomena (astro-ph.HE), education.field_of_study, Multidisciplinary, Vela Pulsar Wind Nebula, AGILE, gamma-rays, Gamma ray, Astronomy, Physics::Space Physics, Astrophysics - High Energy Astrophysical Phenomena, Phenomenology (particle physics), X-ray pulsar
Abstract

Pulsars are known to power winds of relativistic particles that can produce bright nebulae by interacting with the surrounding medium. These pulsar wind nebulae (PWNe) are observed in the radio, optical, x-rays and, in some cases, also at TeV energies, but the lack of information in the gamma-ray band prevents from drawing a comprehensive multiwavelength picture of their phenomenology and emission mechanisms. Using data from the AGILE satellite, we detected the Vela pulsar wind nebula in the energy range from 100 MeV to 3 GeV. This result constrains the particle population responsible for the GeV emission, probing multivavelength PWN models, and establishes a class of gamma-ray emitters that could account for a fraction of the unidentified Galactic gamma-ray sources., Comment: Accepted by Science; first published online on December 31, 2009 in Science Express. Science article and Supporting Online Material are available at http://www.sciencemag.org

Published
2009
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20. AGILE detection of GeV $\sf$γ-ray emission from the SNR W28

Author

A. Giuliani, M. Tavani, A. Bulgarelli, E. Striani, S. Sabatini, M. Cardillo, Y. Fukui, A. Kawamura, A. Ohama, N. Furukawa, K. Torii, H. Sano, F. A. Aharonian, F. Verrecchia, A. Argan, G. Barbiellini, P. A. Caraveo, P. W. Cattaneo, A. W. Chen, V. Cocco, E. Costa, F. D'Ammando, E. Del Monte, G. De Paris, G. Di Cocco, I. Donnarumma, Y. Evangelista, M. Feroci, M. Fiorini, T. Froysland, F. Fuschino, M. Galli, F. Gianotti, C. Labanti, Y. Lapshov, F. Lazzarotto, P. Lipari, F. Longo, M. Marisaldi, S. Mereghetti, A. Morselli, E. Moretti, L. Pacciani, A. Pellizzoni, F. Perotti, P. Picozza, M. Pilia, M. Prest, G. Pucella, M. Rapisarda, A. Rappoldi, P. Soffitta, M. Trifoglio, A. Trois, E. Vallazza, S. Vercellone, V. Vittorini, A. Zambra, D. Zanello, C. Pittori, P. Santolamazza, P. Giommi, S. Colafrancesco, L. Salotti, A., Giuliani, M., Tavani, A., Bulgarelli, E., Striani, S., Sabatini, M., Cardillo, Y., Fukui, A., Kawamura, A., Ohama, N., Furukawa, K., Torii, H., Sano, F. A., Aharonian, F., Verrecchia, A., Argan, G., Barbiellini, P. A., Caraveo, P. W., Cattaneo, A. W., Chen, V., Cocco, E., Costa, F., D'Ammando, E. D., Monte, G. D., Pari, G. D., Cocco, I., Donnarumma, Y., Evangelista, M., Feroci, M., Fiorini, T., Froysland, F., Fuschino, M., Galli, F., Gianotti, C., Labanti, Y., Lapshov, F., Lazzarotto, P., Lipari, Longo, Francesco, M., Marisaldi, S., Mereghetti, A., Morselli, E., Moretti, L., Pacciani, A., Pellizzoni, F., Perotti, P., Picozza, M., Pilia, M., Prest, G., Pucella, M., Rapisarda, A., Rappoldi, P., Soffitta, M., Trifoglio, A., Troi, E., Vallazza, S., Vercellone, V., Vittorini, A., Zambra, D., Zanello, C., Pittori, P., Santolamazza, P., Giommi, S., Colafrancesco, L., Salotti, Giuliani A, Tavani M, Bulgarelli A, Striani E, Sabatini S, Cardillo M, Fukui Y, Kawamura A, Ohama A, Furukawa N, Torii K, Sano H, Aharonian FA, Verrecchia F, Argan A, Barbiellini G, Caraveo PA, Cattaneo PW, Chen AW, Cocco V, Costa E, DAmmando F, Del Monte E, De Paris G, Di Cocco G, Donnarumma I, Evangelista Y, Feroci M, Fiorini M, Froysland T, Fuschino F, Galli M, Gianotti F, Labanti C, Lapshov Y, Lazzarotto F, Lipari P, Longo F, Marisaldi M, Mereghetti S, Morselli A, Moretti E, Pacciani L, Pellizzoni A, Perotti F, Picozza P, Pilia M, Prest M, Pucella G, Rapisarda M, Rappoldi A, Soffitta P, Trifoglio M, Trois A, Vallazza E, Vercellone S, Vittorini V, Zambra A, Zanello D, Pittori C, Santolamazza P, Giommi P, Colafrancesco S, and Salotti L

Subjects
Supernova Remnants, Supernova, Astrophysics::High Energy Astrophysical Phenomena, Hadron, acceleration of particles – diffusion – ISM: supernova remnants – gamma rays: ISM, FOS: Physical sciences, Flux, Cosmic ray, Astrophysics, AGILE, galactic cosmic rays, High Energy Gamma-ray Astronomy, Spectral line, law.invention, Telescope, law, Astrophysics::Galaxy Astrophysics, High Energy Astrophysical Phenomena (astro-ph.HE), Physics, Molecular cloud, AGILE satellite, Gamma ray, Astronomy and Astrophysics, Space and Planetary Science, Astrophysics - High Energy Astrophysical Phenomena
Abstract

Supernova remnants (SNRs) are believed to be the main sources of Galactic cosmic rays. Molecular clouds associated with SNRs can produce gamma-ray emission through the interaction of accelerated particles with the concentrated gas. The middle aged SNR W28, for its associated system of dense molecular clouds, provides an excellent opportunity to test this hypothesis. We present the AGILE/GRID observations of SNR W28, and compare them with observations at other wavelengths (TeV and 12CO J=1-->0 molecular line emission). The gamma-ray flux detected by AGILE from the dominant source associated with W28 is (14 +- 5) 10^-8 ph cm^-2 s^-1 for E > 400 MeV. This source is positionally well correlated with the TeV emission observed by the HESS telescope. The local variations of the GeV to TeV flux ratio suggest a difference between the CR spectra of the north-west and south molecular cloud complexes. A model based on a hadronic-induced interaction and diffusion with two molecular clouds at different distances from the W28 shell can explain both the morphological and spectral features observed by AGILE in the MeV-GeV energy range and by the HESS telescope in the TeV energy range. The combined set of AGILE and H.E.S.S. data strongly support a hadronic model for the gamma-ray production in W28., Accepted for publication in Astronomy & Astrophysics Letters

Published
2010
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