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10 results on '"Hovatta, T"'

1. Multi-wavelength observations of the flaring gamma-ray blazar 3C 66A in 2008 October

Author

Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Johannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Scargle, J. D., Sgro, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., Perez, I. D., Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Tesic, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lahteenmaki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Da Rio, D., Di Paola, A., Diltz, C., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanaa, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., Fermi-Lat Collaboration, Veritas Collaboration Gasp-Webt Consortium, Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Johannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Scargle, J. D., Sgro, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., Perez, I. D., Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Tesic, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lahteenmaki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Da Rio, D., Di Paola, A., Diltz, C., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanaa, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., and Fermi-Lat Collaboration, Veritas Collaboration Gasp-Webt Consortium

Abstract

The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fitted using standard leptonic models with and without an external radiation field for inverse Compton scattering. It is found, however, that only the model with an external radiation field can accommodate the intra-night variability observed at optical wavelengths.

Published
2011

2. Multi-wavelength observations of the flaring gamma-ray blazar 3C 66A in 2008 October

Author

Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Johannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Scargle, J. D., Sgro, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., Perez, I. D., Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Tesic, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lahteenmaki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Da Rio, D., Di Paola, A., Diltz, C., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanaa, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., Fermi-Lat Collaboration, Veritas Collaboration Gasp-Webt Consortium, Abdo, A. A., Ackermann, M., Ajello, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Bechtol, K., Bellazzini, R., Berenji, B., Blandford, R. D., Bonamente, E., Borgland, A. W., Bouvier, A., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Buehler, R., Buson, S., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Carrigan, S., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Charles, E., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Costamante, L., Cutini, S., Davis, D. S., Dermer, C. D., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Favuzzi, C., Fegan, S. J., Fortin, P., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grove, J. E., Guillemot, L., Guiriec, S., Hadasch, D., Hayashida, M., Hays, E., Horan, D., Hughes, R. E., Itoh, R., Johannesson, G., Johnson, A. S., Johnson, T. J., Johnson, W. N., Kamae, T., Katagiri, H., Kataoka, J., Knodlseder, J., Kuss, M., Lande, J., Latronico, L., Lee, S. H., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Makeev, A., Mazziotta, M. N., McEnery, J. E., Mehault, J., Michelson, P. F., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nakamori, T., Naumann-Godo, M., Nestoras, I., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Okumura, A., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Reimer, A., Reimer, O., Reyes, L. C., Ripken, J., Ritz, S., Romani, R. W., Roth, M., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Scargle, J. D., Sgro, C., Shaw, M. S., Smith, P. D., Spandre, G., Spinelli, P., Strickman, M. S., Suson, D. J., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Torres, D. F., Tosti, G., Tramacere, A., Usher, T. L., Vandenbroucke, J., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yang, Z., Ylinen, T., Ziegler, M., Acciari, V. A., Aliu, E., Arlen, T., Aune, T., Beilicke, M., Benbow, W., Bottcher, M., Boltuch, D., Bradbury, S. M., Buckley, J. H., Bugaev, V., Byrum, K., Cannon, A., Cesarini, A., Christiansen, J. L., Ciupik, L., Cui, W., Perez, I. D., Dickherber, R., Errando, M., Falcone, A., Finley, J. P., Finnegan, G., Fortson, L., Furniss, A., Galante, N., Gall, D., Gillanders, G. H., Godambe, S., Grube, J., Guenette, R., Gyuk, G., Hanna, D., Holder, J., Hui, C. M., Humensky, T. B., Imran, A., Kaaret, P., Karlsson, N., Kertzman, M., Kieda, D., Konopelko, A., Krawczynski, H., Krennrich, F., Lang, M. J., LeBohec, S., Maier, G., McArthur, S., McCann, A., McCutcheon, M., Moriarty, P., Mukherjee, R., Ong, R. A., Otte, A. N., Pandel, D., Perkins, J. S., Pichel, A., Pohl, M., Quinn, J., Ragan, K., Reynolds, P. T., Roache, E., Rose, H. J., Schroedter, M., Sembroski, G. H., Senturk, G. D., Smith, A. W., Steele, D., Swordy, S. P., Tesic, G., Theiling, M., Thibadeau, S., Varlotta, A., Vassiliev, V. V., Vincent, S., Wakely, S. P., Ward, J. E., Weekes, T. C., Weinstein, A., Weisgarber, T., Williams, D. A., Wissel, S., Wood, M., Villata, M., Raiteri, C. M., Gurwell, M. A., Larionov, V. M., Kurtanidze, O. M., Aller, M. F., Lahteenmaki, A., Chen, W. P., Berduygin, A., Agudo, I., Aller, H. D., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Buemi, C. S., Dashti, J., Calcidese, P., Capezzali, D., Carosati, D., Da Rio, D., Di Paola, A., Diltz, C., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G. N., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mommert, M., Mujica, R., Nikolashvili, M. G., Nilsson, K., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L. A., Sillanaa, A., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Belloni, T., Blake, C. H., Bloom, J. S., Angelakis, E., Fumagalli, M., Hauser, M., Prochaska, J. X., Riquelme, D., Sievers, A., Starr, D. L., Tagliaferri, G., Ungerechts, H., Wagner, S., Zensus, J. A., and Fermi-Lat Collaboration, Veritas Collaboration Gasp-Webt Consortium

Abstract

The BL Lacertae object 3C 66A was detected in a flaring state by the Fermi Large Area Telescope (LAT) and VERITAS in 2008 October. In addition to these gamma-ray observations, F-GAMMA, GASP-WEBT, PAIRITEL, MDM, ATOM, Swift, and Chandra provided radio to X-ray coverage. The available light curves show variability and, in particular, correlated flares are observed in the optical and Fermi-LAT gamma-ray band. The resulting spectral energy distribution can be well fitted using standard leptonic models with and without an external radiation field for inverse Compton scattering. It is found, however, that only the model with an external radiation field can accommodate the intra-night variability observed at optical wavelengths.

Published
2011

3. PKS 1502+106: A new and distant gamma-ray blazar in outburst discovered by the Fermi large area telescope

Author

Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bogaert, G., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dermer, C. D., de Angelis, A., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. H., Grove, J. E., Guillemot, L., Guiriec, S., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Johnson, W. N., Kadler, M., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knodlseder, J., Kocian, M. L., Kuehn, F., Kuss, M., Lande, J., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Marelli, M., Massaro, E., Max-Moerbeck, W., Mazziotta, M. N., McConville, W., McEnery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pavlidou, V., Pearson, T. J., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Readhead, A., Reimer, A., Reimer, O., Reposeur, T., Richards, J. L., Ritz, S., Rochester, L. S., Rodriguez, A. Y., Romani, R. W., Roth, M., Ryde, F., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Parkinson, P. M. S., Scargle, J. D., Sgro, C., Shaw, M. S., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Stevenson, M., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Ubertini, P., Uchiyama, Y., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yasuda, H., Ylinen, T., Zensus, J. A., Ziegler, M., Angelakis, E., Hovatta, T., Hoversten, E., Ikejiri, Y., Kawabata, K. S., Kovalev, Y. Y., Kovalev, Y. A., Krichbaum, T. P., Lister, M. L., Lahteenmaki, A., Marchili, N., Ogle, P., Pagani, C., Pushkarev, A. B., Sakimoto, K., Sasada, M., Tornikoski, M., Uemura, M., Yamanaka, M., Yamashita, T., Fermi Lat, Collaboration, Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bogaert, G., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dermer, C. D., de Angelis, A., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. H., Grove, J. E., Guillemot, L., Guiriec, S., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Johnson, W. N., Kadler, M., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knodlseder, J., Kocian, M. L., Kuehn, F., Kuss, M., Lande, J., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Marelli, M., Massaro, E., Max-Moerbeck, W., Mazziotta, M. N., McConville, W., McEnery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pavlidou, V., Pearson, T. J., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Readhead, A., Reimer, A., Reimer, O., Reposeur, T., Richards, J. L., Ritz, S., Rochester, L. S., Rodriguez, A. Y., Romani, R. W., Roth, M., Ryde, F., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Parkinson, P. M. S., Scargle, J. D., Sgro, C., Shaw, M. S., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Stevenson, M., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Ubertini, P., Uchiyama, Y., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yasuda, H., Ylinen, T., Zensus, J. A., Ziegler, M., Angelakis, E., Hovatta, T., Hoversten, E., Ikejiri, Y., Kawabata, K. S., Kovalev, Y. Y., Kovalev, Y. A., Krichbaum, T. P., Lister, M. L., Lahteenmaki, A., Marchili, N., Ogle, P., Pagani, C., Pushkarev, A. B., Sakimoto, K., Sasada, M., Tornikoski, M., Uemura, M., Yamanaka, M., Yamashita, T., and Fermi Lat, Collaboration

Abstract

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope discovered a rapid (similar to 5 days duration), high-energy (E > 100 MeV) gamma-ray outburst from a source identified with the blazar PKS 1502+106 (OR 103, S3 1502+10, z = 1.839) starting on 2008 August 5 (similar to 23 UTC, MJD 54683.95), and followed by bright and variable flux over the next few months. Results on the gamma-ray localization and identification, as well as spectral and temporal behavior during the first months of the Fermi all-sky survey, are reported here in conjunction with a multiwaveband characterization as a result of one of the first Fermi multifrequency campaigns. The campaign included a Swift ToO (followed up by a 16 day observation on August 7-22, MJD 54685-54700), VLBA (within the MOJAVE program), Owens Valley Radio Observatory (OVRO) 40 m, Effelsberg-100 m, Metsahovi-14 m, RATAN-600, and Kanata-Hiroshima radio/optical observations. Results from the analysis of archival observations by INTEGRAL, XMM-Newton, and Spitzer space telescopes are reported for a more complete picture of this new gamma-ray blazar. PKS 1502+106 is a sub-GeV peaked, powerful flat spectrum radio quasar (luminosity at E > 100 MeV, L-gamma, is about 1.1 x 10(49) erg s(-1), and black hole mass likely close to 10(9) M-circle dot), exhibiting marked gamma-ray bolometric dominance, in particular during the asymmetric outburst (L-gamma/L-opt similar to 100, and 5 day averaged flux F-E > 100MeV = 2.91 +/- 1.4 x 10(-6) ph cm(-2) s(-1)), which was characterized by a factor greater than 3 of flux increase in less than 12 hr. The outburst was observed simultaneously from optical to X-ray bands (F0.3-10keV = 2.18(-0.12)(+0.15) x 10(-12) erg cm(-2) s(-1), and hard photon index similar to 1.5, similar to past values) with a flux increase of less than 1 order of magnitude with respect to past observations, and was likely controlled by Comptonization of external-jet photons produced in the broad-line region (

Published
2010

4. Relativistic beaming and gamma-ray brightness of blazars

Author

Savolainen, T., Homan, D. C., Hovatta, T., Kadler, M., Kovalev, Y. Y., Lister, M. L., Ros, E., Zensus, J. A., Savolainen, T., Homan, D. C., Hovatta, T., Kadler, M., Kovalev, Y. Y., Lister, M. L., Ros, E., and Zensus, J. A.

Abstract

Aims. We investigate the dependence of gamma-ray brightness of blazars on intrinsic properties of their parsec-scale radio jets and the implication for relativistic beaming. Methods. By combining apparent jet speeds derived from high-resolution VLBA images from the MOJAVE program with millimetre-wavelength flux density monitoring data from Metsahovi Radio Observatory, we estimate the jet Doppler factors, Lorentz factors, and viewing angles for a sample of 62 blazars. We study the trends in these quantities between the sources which were detected in gamma-rays by the Fermi Large Area Telescope (LAT) during its first three months of science operations and those which were not detected. Results. The LAT-detected blazars have on average higher Doppler factors than non-LAT-detected blazars, as has been implied indirectly in several earlier studies. We find statistically significant differences in the viewing angle distributions between gamma-ray bright and weak sources. Most interestingly, gamma-ray bright blazars have a distribution of comoving frame viewing angles that is significantly narrower than that of gamma-ray weak blazars and centred roughly perpendicular to the jet axis. The lack of gamma-ray bright blazars at large comoving frame viewing angles can be explained by relativistic beaming of gamma-rays, while the apparent lack of gamma-ray bright blazars at small comoving frame viewing angles, if confirmed with larger samples, may suggest an intrinsic anisotropy or Lorentz factor dependence of the gamma-ray emission.

Published
2010

5. Multiwavelength observations of 3C 454.3. III. Eighteen months of agile monitoring of the 'Crazy Diamond'

Author

Vercellone, S., D'Ammando, F., Vittorini, V., Donnarumma, I., Pucella, G., Tavani, M., Ferrari, A., Raiteri, C. M., Villata, M., Romano, P., Krimm, H., Tiengo, A., Chen, A. W., Giovannini, G., Venturi, T., Giroletti, M., Kovalev, Y. Y., Sokolovsky, K., Pushkarev, A. B., Lister, M. L., Argan, A., Barbiellini, G., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Fornari, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Giuliani, A., Marisaldi, M., Mereghetti, S., Morselli, A., Pellizzoni, A., Pacciani, L., Perotti, F., Piano, G., 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., Pittori, C., Verrecchia, F., Santolamazza, P., Giommi, P., Colafrancesco, S., Salotti, L., Agudo, I., Aller, H. D., Aller, M. F., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Bottcher, M., Buemi, C. S., Calcidese, P., Capezzali, D., Carosati, D., Chen, W. P., Da Rio, D., Di Paola, A., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Gurwell, M. A., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O., Lahteenmaki, A., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mujica, R., Nikolashvili, M., Nilsson, K., Mommert, M., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Vercellone, S., D'Ammando, F., Vittorini, V., Donnarumma, I., Pucella, G., Tavani, M., Ferrari, A., Raiteri, C. M., Villata, M., Romano, P., Krimm, H., Tiengo, A., Chen, A. W., Giovannini, G., Venturi, T., Giroletti, M., Kovalev, Y. Y., Sokolovsky, K., Pushkarev, A. B., Lister, M. L., Argan, A., Barbiellini, G., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Fornari, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Giuliani, A., Marisaldi, M., Mereghetti, S., Morselli, A., Pellizzoni, A., Pacciani, L., Perotti, F., Piano, G., 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., Pittori, C., Verrecchia, F., Santolamazza, P., Giommi, P., Colafrancesco, S., Salotti, L., Agudo, I., Aller, H. D., Aller, M. F., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Bottcher, M., Buemi, C. S., Calcidese, P., Capezzali, D., Carosati, D., Chen, W. P., Da Rio, D., Di Paola, A., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Gurwell, M. A., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O., Lahteenmaki, A., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mujica, R., Nikolashvili, M., Nilsson, K., Mommert, M., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., and Umana, G.

Abstract

We report on 18 months of multiwavelength observations of the blazar 3C 454.3 ( Crazy Diamond) carried out in the period 2007 July-2009 January. In particular, we show the results of the AGILE campaigns which took place on 2008 May-June, 2008 July-August, and 2008 October-2009 January. During the 2008 May-2009 January period, the source average flux was highly variable, with a clear fading trend toward the end of the period, from an average. gamma-ray flux F-E>100 (MeV) greater than or similar to 200 x 10(-8) photons cm(-2) s(-1) in 2008 May-June, to F-E>100 MeV similar to 80 x 10(-8) photons cm(-2) s(-1) in 2008 October-2009 January. The average gamma-ray spectrum between 100 MeV and 1 GeV can be fit by a simple power law, showing a moderate softening ( from Gamma(GRID) similar to 2.0 to Gamma(GRID) similar to 2.2) toward the end of the observing campaign. Only 3 sigma upper limits can be derived in the 20-60 keV energy band with Super-AGILE, because the source was considerably off-axis during the whole time period. In 2007 July-August and 2008 May-June, 3C 454.3 was monitored by Rossi X-ray Timing Explorer (RXTE). The RXTE/Proportional Counter Array (PCA) light curve in the 3-20 keV energy band shows variability correlated with the gamma-ray one. The RXTE/PCA average flux during the two time periods is F3-20 keV = 8.4 x 10(-11) erg cm(-2) s(-1), and F3-20 keV = 4.5 x 10(-11) erg cm(-2) s(-1), respectively, while the spectrum ( a power law with photon index Gamma(PCA) = 1.65 +/- 0.02) does not show any significant variability. Consistent results are obtained with the analysis of the RXTE/High-Energy X-Ray Timing Experiment quasi-simultaneous data. We also carried out simultaneous Swift observations during all AGILE campaigns. Swift/XRT detected 3C 454.3 with an observed flux in the 2-10 keV energy band in the range (0.9-7.5) x 10(-11) erg cm(-2) s(-1) and a photon index in the range Gamma(XRT) = 1.33-2.04. In the 15-150 keV energy band, when detected, the source ha

Published
2010

6. The relation between radio polarization and gamma-ray emission in AGN jets

Author

Hovatta, T., Lister, M. L., Kovalev, Y. Y., Pushkarev, A. B., Savolainen, T., Hovatta, T., Lister, M. L., Kovalev, Y. Y., Pushkarev, A. B., and Savolainen, T.

Abstract

We have compared the parsec-scale jet linear polarization properties of the Fermi LAT-detected and non-detected sources in the complete flux-density-limited (MOJAVE-1) sample of highly beamed AGN. Of the 123 MOJAVE sources, 30 were detected by the LAT during its first three months of operation. We find that during the era since the launch of Fermi, the unresolved core components of the LAT-detected jets have significantly higher median fractional polarization at 15 GHz. This complements our previous findings that these LAT sources have higher apparent jet speeds, brightness temperatures and Doppler factors, and are preferentially found in higher activity states.

Published
2010

7. The relation between radio polarization and gamma-ray emission in AGN jets

Author

Hovatta, T., Lister, M. L., Kovalev, Y. Y., Pushkarev, A. B., Savolainen, T., Hovatta, T., Lister, M. L., Kovalev, Y. Y., Pushkarev, A. B., and Savolainen, T.

Abstract

We have compared the parsec-scale jet linear polarization properties of the Fermi LAT-detected and non-detected sources in the complete flux-density-limited (MOJAVE-1) sample of highly beamed AGN. Of the 123 MOJAVE sources, 30 were detected by the LAT during its first three months of operation. We find that during the era since the launch of Fermi, the unresolved core components of the LAT-detected jets have significantly higher median fractional polarization at 15 GHz. This complements our previous findings that these LAT sources have higher apparent jet speeds, brightness temperatures and Doppler factors, and are preferentially found in higher activity states.

Published
2010

8. PKS 1502+106: A new and distant gamma-ray blazar in outburst discovered by the Fermi large area telescope

Author

Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bogaert, G., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dermer, C. D., de Angelis, A., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. H., Grove, J. E., Guillemot, L., Guiriec, S., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Johnson, W. N., Kadler, M., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knodlseder, J., Kocian, M. L., Kuehn, F., Kuss, M., Lande, J., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Marelli, M., Massaro, E., Max-Moerbeck, W., Mazziotta, M. N., McConville, W., McEnery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pavlidou, V., Pearson, T. J., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Readhead, A., Reimer, A., Reimer, O., Reposeur, T., Richards, J. L., Ritz, S., Rochester, L. S., Rodriguez, A. Y., Romani, R. W., Roth, M., Ryde, F., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Parkinson, P. M. S., Scargle, J. D., Sgro, C., Shaw, M. S., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Stevenson, M., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Ubertini, P., Uchiyama, Y., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yasuda, H., Ylinen, T., Zensus, J. A., Ziegler, M., Angelakis, E., Hovatta, T., Hoversten, E., Ikejiri, Y., Kawabata, K. S., Kovalev, Y. Y., Kovalev, Y. A., Krichbaum, T. P., Lister, M. L., Lahteenmaki, A., Marchili, N., Ogle, P., Pagani, C., Pushkarev, A. B., Sakimoto, K., Sasada, M., Tornikoski, M., Uemura, M., Yamanaka, M., Yamashita, T., Fermi Lat, Collaboration, Abdo, A. A., Ackermann, M., Ajello, M., Atwood, W. B., Axelsson, M., Baldini, L., Ballet, J., Barbiellini, G., Bastieri, D., Baughman, B. M., Bechtol, K., Bellazzini, R., Berenji, B., Bloom, E. D., Bogaert, G., Bonamente, E., Borgland, A. W., Bregeon, J., Brez, A., Brigida, M., Bruel, P., Burnett, T. H., Caliandro, G. A., Cameron, R. A., Caraveo, P. A., Casandjian, J. M., Cavazzuti, E., Cecchi, C., Celik, O., Chekhtman, A., Cheung, C. C., Chiang, J., Ciprini, S., Claus, R., Cohen-Tanugi, J., Conrad, J., Cutini, S., Dermer, C. D., de Angelis, A., de Palma, F., Digel, S. W., Silva, E. D. E., Drell, P. S., Dubois, R., Dumora, D., Farnier, C., Favuzzi, C., Fegan, S. J., Ferrara, E. C., Focke, W. B., Frailis, M., Fuhrmann, L., Fukazawa, Y., Funk, S., Fusco, P., Gargano, F., Gasparrini, D., Gehrels, N., Germani, S., Giebels, B., Giglietto, N., Giordano, F., Giroletti, M., Glanzman, T., Godfrey, G., Grenier, I. A., Grondin, M. H., Grove, J. E., Guillemot, L., Guiriec, S., Hanabata, Y., Harding, A. K., Hayashida, M., Hays, E., Hughes, R. E., Johannesson, G., Johnson, A. S., Johnson, R. P., Johnson, W. N., Kadler, M., Kamae, T., Katagiri, H., Kataoka, J., Kerr, M., Knodlseder, J., Kocian, M. L., Kuehn, F., Kuss, M., Lande, J., Latronico, L., Lemoine-Goumard, M., Longo, F., Loparco, F., Lott, B., Lovellette, M. N., Lubrano, P., Madejski, G. M., Makeev, A., Marelli, M., Massaro, E., Max-Moerbeck, W., Mazziotta, M. N., McConville, W., McEnery, J. E., Meurer, C., Michelson, P. F., Mitthumsiri, W., Mizuno, T., Moiseev, A. A., Monte, C., Monzani, M. E., Morselli, A., Moskalenko, I. V., Murgia, S., Nolan, P. L., Norris, J. P., Nuss, E., Ohsugi, T., Omodei, N., Orlando, E., Ormes, J. F., Ozaki, M., Paneque, D., Panetta, J. H., Parent, D., Pavlidou, V., Pearson, T. J., Pelassa, V., Pepe, M., Pesce-Rollins, M., Piron, F., Porter, T. A., Raino, S., Rando, R., Razzano, M., Razzaque, S., Readhead, A., Reimer, A., Reimer, O., Reposeur, T., Richards, J. L., Ritz, S., Rochester, L. S., Rodriguez, A. Y., Romani, R. W., Roth, M., Ryde, F., Sadrozinski, H. F. W., Sanchez, D., Sander, A., Parkinson, P. M. S., Scargle, J. D., Sgro, C., Shaw, M. S., Siskind, E. J., Smith, D. A., Smith, P. D., Spandre, G., Spinelli, P., Stevenson, M., Strickman, M. S., Suson, D. J., Tajima, H., Takahashi, H., Tanaka, T., Thayer, J. B., Thayer, J. G., Thompson, D. J., Tibaldo, L., Tibolla, O., Torres, D. F., Tosti, G., Tramacere, A., Ubertini, P., Uchiyama, Y., Usher, T. L., Vasileiou, V., Vilchez, N., Vitale, V., Waite, A. P., Wang, P., Winer, B. L., Wood, K. S., Yasuda, H., Ylinen, T., Zensus, J. A., Ziegler, M., Angelakis, E., Hovatta, T., Hoversten, E., Ikejiri, Y., Kawabata, K. S., Kovalev, Y. Y., Kovalev, Y. A., Krichbaum, T. P., Lister, M. L., Lahteenmaki, A., Marchili, N., Ogle, P., Pagani, C., Pushkarev, A. B., Sakimoto, K., Sasada, M., Tornikoski, M., Uemura, M., Yamanaka, M., Yamashita, T., and Fermi Lat, Collaboration

Abstract

The Large Area Telescope (LAT) on board the Fermi Gamma-ray Space Telescope discovered a rapid (similar to 5 days duration), high-energy (E > 100 MeV) gamma-ray outburst from a source identified with the blazar PKS 1502+106 (OR 103, S3 1502+10, z = 1.839) starting on 2008 August 5 (similar to 23 UTC, MJD 54683.95), and followed by bright and variable flux over the next few months. Results on the gamma-ray localization and identification, as well as spectral and temporal behavior during the first months of the Fermi all-sky survey, are reported here in conjunction with a multiwaveband characterization as a result of one of the first Fermi multifrequency campaigns. The campaign included a Swift ToO (followed up by a 16 day observation on August 7-22, MJD 54685-54700), VLBA (within the MOJAVE program), Owens Valley Radio Observatory (OVRO) 40 m, Effelsberg-100 m, Metsahovi-14 m, RATAN-600, and Kanata-Hiroshima radio/optical observations. Results from the analysis of archival observations by INTEGRAL, XMM-Newton, and Spitzer space telescopes are reported for a more complete picture of this new gamma-ray blazar. PKS 1502+106 is a sub-GeV peaked, powerful flat spectrum radio quasar (luminosity at E > 100 MeV, L-gamma, is about 1.1 x 10(49) erg s(-1), and black hole mass likely close to 10(9) M-circle dot), exhibiting marked gamma-ray bolometric dominance, in particular during the asymmetric outburst (L-gamma/L-opt similar to 100, and 5 day averaged flux F-E > 100MeV = 2.91 +/- 1.4 x 10(-6) ph cm(-2) s(-1)), which was characterized by a factor greater than 3 of flux increase in less than 12 hr. The outburst was observed simultaneously from optical to X-ray bands (F0.3-10keV = 2.18(-0.12)(+0.15) x 10(-12) erg cm(-2) s(-1), and hard photon index similar to 1.5, similar to past values) with a flux increase of less than 1 order of magnitude with respect to past observations, and was likely controlled by Comptonization of external-jet photons produced in the broad-line region (

Published
2010

9. Relativistic beaming and gamma-ray brightness of blazars

Author

Savolainen, T., Homan, D. C., Hovatta, T., Kadler, M., Kovalev, Y. Y., Lister, M. L., Ros, E., Zensus, J. A., Savolainen, T., Homan, D. C., Hovatta, T., Kadler, M., Kovalev, Y. Y., Lister, M. L., Ros, E., and Zensus, J. A.

Abstract

Aims. We investigate the dependence of gamma-ray brightness of blazars on intrinsic properties of their parsec-scale radio jets and the implication for relativistic beaming. Methods. By combining apparent jet speeds derived from high-resolution VLBA images from the MOJAVE program with millimetre-wavelength flux density monitoring data from Metsahovi Radio Observatory, we estimate the jet Doppler factors, Lorentz factors, and viewing angles for a sample of 62 blazars. We study the trends in these quantities between the sources which were detected in gamma-rays by the Fermi Large Area Telescope (LAT) during its first three months of science operations and those which were not detected. Results. The LAT-detected blazars have on average higher Doppler factors than non-LAT-detected blazars, as has been implied indirectly in several earlier studies. We find statistically significant differences in the viewing angle distributions between gamma-ray bright and weak sources. Most interestingly, gamma-ray bright blazars have a distribution of comoving frame viewing angles that is significantly narrower than that of gamma-ray weak blazars and centred roughly perpendicular to the jet axis. The lack of gamma-ray bright blazars at large comoving frame viewing angles can be explained by relativistic beaming of gamma-rays, while the apparent lack of gamma-ray bright blazars at small comoving frame viewing angles, if confirmed with larger samples, may suggest an intrinsic anisotropy or Lorentz factor dependence of the gamma-ray emission.

Published
2010

10. Multiwavelength observations of 3C 454.3. III. Eighteen months of agile monitoring of the 'Crazy Diamond'

Author

Vercellone, S., D'Ammando, F., Vittorini, V., Donnarumma, I., Pucella, G., Tavani, M., Ferrari, A., Raiteri, C. M., Villata, M., Romano, P., Krimm, H., Tiengo, A., Chen, A. W., Giovannini, G., Venturi, T., Giroletti, M., Kovalev, Y. Y., Sokolovsky, K., Pushkarev, A. B., Lister, M. L., Argan, A., Barbiellini, G., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Fornari, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Giuliani, A., Marisaldi, M., Mereghetti, S., Morselli, A., Pellizzoni, A., Pacciani, L., Perotti, F., Piano, G., 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., Pittori, C., Verrecchia, F., Santolamazza, P., Giommi, P., Colafrancesco, S., Salotti, L., Agudo, I., Aller, H. D., Aller, M. F., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Bottcher, M., Buemi, C. S., Calcidese, P., Capezzali, D., Carosati, D., Chen, W. P., Da Rio, D., Di Paola, A., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Gurwell, M. A., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O., Lahteenmaki, A., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mujica, R., Nikolashvili, M., Nilsson, K., Mommert, M., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., Umana, G., Vercellone, S., D'Ammando, F., Vittorini, V., Donnarumma, I., Pucella, G., Tavani, M., Ferrari, A., Raiteri, C. M., Villata, M., Romano, P., Krimm, H., Tiengo, A., Chen, A. W., Giovannini, G., Venturi, T., Giroletti, M., Kovalev, Y. Y., Sokolovsky, K., Pushkarev, A. B., Lister, M. L., Argan, A., Barbiellini, G., Bulgarelli, A., Caraveo, P., Cattaneo, P. W., Cocco, V., Costa, E., Del Monte, E., De Paris, G., Di Cocco, G., Evangelista, Y., Feroci, M., Fiorini, M., Fornari, F., Froysland, T., Fuschino, F., Galli, M., Gianotti, F., Labanti, C., Lapshov, I., Lazzarotto, F., Lipari, P., Longo, F., Giuliani, A., Marisaldi, M., Mereghetti, S., Morselli, A., Pellizzoni, A., Pacciani, L., Perotti, F., Piano, G., 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., Pittori, C., Verrecchia, F., Santolamazza, P., Giommi, P., Colafrancesco, S., Salotti, L., Agudo, I., Aller, H. D., Aller, M. F., Arkharov, A. A., Bach, U., Bachev, R., Beltrame, P., Benitez, E., Bottcher, M., Buemi, C. S., Calcidese, P., Capezzali, D., Carosati, D., Chen, W. P., Da Rio, D., Di Paola, A., Dolci, M., Dultzin, D., Forne, E., Gomez, J. L., Gurwell, M. A., Hagen-Thorn, V. A., Halkola, A., Heidt, J., Hiriart, D., Hovatta, T., Hsiao, H. Y., Jorstad, S. G., Kimeridze, G., Konstantinova, T. S., Kopatskaya, E. N., Koptelova, E., Kurtanidze, O., Lahteenmaki, A., Larionov, V. M., Leto, P., Ligustri, R., Lindfors, E., Lopez, J. M., Marscher, A. P., Mujica, R., Nikolashvili, M., Nilsson, K., Mommert, M., Palma, N., Pasanen, M., Roca-Sogorb, M., Ros, J. A., Roustazadeh, P., Sadun, A. C., Saino, J., Sigua, L., Sorcia, M., Takalo, L. O., Tornikoski, M., Trigilio, C., Turchetti, R., and Umana, G.

Abstract

We report on 18 months of multiwavelength observations of the blazar 3C 454.3 ( Crazy Diamond) carried out in the period 2007 July-2009 January. In particular, we show the results of the AGILE campaigns which took place on 2008 May-June, 2008 July-August, and 2008 October-2009 January. During the 2008 May-2009 January period, the source average flux was highly variable, with a clear fading trend toward the end of the period, from an average. gamma-ray flux F-E>100 (MeV) greater than or similar to 200 x 10(-8) photons cm(-2) s(-1) in 2008 May-June, to F-E>100 MeV similar to 80 x 10(-8) photons cm(-2) s(-1) in 2008 October-2009 January. The average gamma-ray spectrum between 100 MeV and 1 GeV can be fit by a simple power law, showing a moderate softening ( from Gamma(GRID) similar to 2.0 to Gamma(GRID) similar to 2.2) toward the end of the observing campaign. Only 3 sigma upper limits can be derived in the 20-60 keV energy band with Super-AGILE, because the source was considerably off-axis during the whole time period. In 2007 July-August and 2008 May-June, 3C 454.3 was monitored by Rossi X-ray Timing Explorer (RXTE). The RXTE/Proportional Counter Array (PCA) light curve in the 3-20 keV energy band shows variability correlated with the gamma-ray one. The RXTE/PCA average flux during the two time periods is F3-20 keV = 8.4 x 10(-11) erg cm(-2) s(-1), and F3-20 keV = 4.5 x 10(-11) erg cm(-2) s(-1), respectively, while the spectrum ( a power law with photon index Gamma(PCA) = 1.65 +/- 0.02) does not show any significant variability. Consistent results are obtained with the analysis of the RXTE/High-Energy X-Ray Timing Experiment quasi-simultaneous data. We also carried out simultaneous Swift observations during all AGILE campaigns. Swift/XRT detected 3C 454.3 with an observed flux in the 2-10 keV energy band in the range (0.9-7.5) x 10(-11) erg cm(-2) s(-1) and a photon index in the range Gamma(XRT) = 1.33-2.04. In the 15-150 keV energy band, when detected, the source ha

Published
2010

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