The gamma-ray energy spectra of bright blazars of the LAT Bright AGN Sample LBAS) are investigated using Fermi-LAT data. Spectral properties hardness, curvature, and variability) established using a data set accumulated over 6 months of operation are presented and discussed for different blazar classes and subclasses: flat spectrum radio quasars (FSRQs), low-synchrotron peaked BLLacs (LSP-BLLacs), intermediate-synchrotron peaked BLLacs (ISP-BLLacs), and high-synchrotron peaked BLLacs (HSP-BLLacs). The distribution of photon index G, obtained from a power-law fit above 100 MeV) is found to correlate strongly with blazar subclass. The change in spectral index from that averaged over the 6 months observing period is < 0.2-0.3 when the flux varies by about an order of magnitude, with a tendency toward harder spectra when the flux is brighter for FSRQs and LSP-BLLacs. A strong departure from a single power-law spectrum appears to be a common feature for FSRQs. This feature is also present for some high-luminosity LSP-BLLacs, and a small number of ISP-BLLacs. It is absent in all LBAS HSP-BLLacs. For 3C 454.3 and AO 0235+164, the two brightest FSRQ source and LSP-BLLac source, respectively, a broken power law (BPL) gives the most acceptable of power law, BPL, and curved forms. The consequences of these findings are discussed.

Spectral properties of bright fermi-detected blazars in the gamma-ray band / Abdo, Aa; Ackermann, M; Ajello, M; Atwood, Wb; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, Rd; Bloom, Ed; Bonamente, E; Borgland, Aw; Bouvier, A; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, Th; Buson, S; Caliandro, Ga; Cameron, Ra; Caraveo, Pa; Carrigan, S; Casandjian, Jm; Cavazzuti, E; Cecchi, C; Celik, O; Charles, E; Chekhtman, A; Cheung, Cc; Chiang, J; Ciprini, S; Claus, R; Cohen Tanugi, J; Conrad, J; Cutini, S; Dermer, Cd; de Angelis, A; de Palma, F; Digel, Sw; Silva, Ede; Drell, Ps; Dubois, R; Dumora, D; Farnier, C; Favuzzi, Cecilia; Fegan, Sj; Focke, Wb; Fortin, P; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, Nicola; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, Ia; Grondin, Mh; Grove, Je; Guillemot, L; Guiriec, S; Harding, Ak; Hartman, Rc; Hayashida, M; Hays, E; Healey, Se; Horan, D; Hughes, Re; Jackson, Ms; Johannesson, G; Johnson, As; Johnson, Wn; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knodlseder, J; Kuss, M; Lande, J; Latronico, L; Lemoine Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, Mn; Lubrano, P; Madejski, Gm; Makeev, A; Mazziotta, Mn; Mcconville, W; Mcenery, Je; Meurer, C; Michelson, Pf; Mitthumsiri, W; Mizuno, T; Moiseev, Aa; Monte, C; Monzani, Me; Morselli, A; Moskalenko, Iv; Murgia, S; Nolan, Pl; Norris, Jp; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, Jf; Paneque, D; Panetta, Jh; Parent, D; Pelassa, V; Pepe, M; Persic, M; Pesce Rollins, M; Piron, F; Porter, Ta; Raino, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, Ls; Rodriguez, Ay; Romani, Rw; Roth, M; Ryde, F; Sadrozinski, Hfw; Sanchez, D; Sander, A; Parkinson, Pms; Scargle, Jd; Sgro, C; Siskind, Ej; Smith, Da; Smith, Pd; Spandre, G; Spinelli, P; Strickman, Ms; Suson, Dj; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, Jb; Thayer, Jg; Thompson, Dj; Tibaldo, L; Torres, Df; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, Tl; Vasileiou, V; Vilchez, N; Villata, M; Vitale, V; Waite, Ap; Wang, P; Winer, Bl; Wood, Ks; Ylinen, T; Ziegler, M.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - ELETTRONICO. - 710:2(2010), pp. 1271-1285. [10.1088/0004-637X/710/2/1271]

Spectral properties of bright fermi-detected blazars in the gamma-ray band

FAVUZZI, Cecilia;GIGLIETTO, Nicola;
2010-01-01

Abstract

The gamma-ray energy spectra of bright blazars of the LAT Bright AGN Sample LBAS) are investigated using Fermi-LAT data. Spectral properties hardness, curvature, and variability) established using a data set accumulated over 6 months of operation are presented and discussed for different blazar classes and subclasses: flat spectrum radio quasars (FSRQs), low-synchrotron peaked BLLacs (LSP-BLLacs), intermediate-synchrotron peaked BLLacs (ISP-BLLacs), and high-synchrotron peaked BLLacs (HSP-BLLacs). The distribution of photon index G, obtained from a power-law fit above 100 MeV) is found to correlate strongly with blazar subclass. The change in spectral index from that averaged over the 6 months observing period is < 0.2-0.3 when the flux varies by about an order of magnitude, with a tendency toward harder spectra when the flux is brighter for FSRQs and LSP-BLLacs. A strong departure from a single power-law spectrum appears to be a common feature for FSRQs. This feature is also present for some high-luminosity LSP-BLLacs, and a small number of ISP-BLLacs. It is absent in all LBAS HSP-BLLacs. For 3C 454.3 and AO 0235+164, the two brightest FSRQ source and LSP-BLLac source, respectively, a broken power law (BPL) gives the most acceptable of power law, BPL, and curved forms. The consequences of these findings are discussed.
2010
Spectral properties of bright fermi-detected blazars in the gamma-ray band / Abdo, Aa; Ackermann, M; Ajello, M; Atwood, Wb; Axelsson, M; Baldini, L; Ballet, J; Barbiellini, G; Bastieri, D; Bechtol, K; Bellazzini, R; Berenji, B; Blandford, Rd; Bloom, Ed; Bonamente, E; Borgland, Aw; Bouvier, A; Bregeon, J; Brez, A; Brigida, M; Bruel, P; Burnett, Th; Buson, S; Caliandro, Ga; Cameron, Ra; Caraveo, Pa; Carrigan, S; Casandjian, Jm; Cavazzuti, E; Cecchi, C; Celik, O; Charles, E; Chekhtman, A; Cheung, Cc; Chiang, J; Ciprini, S; Claus, R; Cohen Tanugi, J; Conrad, J; Cutini, S; Dermer, Cd; de Angelis, A; de Palma, F; Digel, Sw; Silva, Ede; Drell, Ps; Dubois, R; Dumora, D; Farnier, C; Favuzzi, Cecilia; Fegan, Sj; Focke, Wb; Fortin, P; Frailis, M; Fukazawa, Y; Funk, S; Fusco, P; Gargano, F; Gasparrini, D; Gehrels, N; Germani, S; Giebels, B; Giglietto, Nicola; Giommi, P; Giordano, F; Glanzman, T; Godfrey, G; Grenier, Ia; Grondin, Mh; Grove, Je; Guillemot, L; Guiriec, S; Harding, Ak; Hartman, Rc; Hayashida, M; Hays, E; Healey, Se; Horan, D; Hughes, Re; Jackson, Ms; Johannesson, G; Johnson, As; Johnson, Wn; Kamae, T; Katagiri, H; Kataoka, J; Kawai, N; Kerr, M; Knodlseder, J; Kuss, M; Lande, J; Latronico, L; Lemoine Goumard, M; Longo, F; Loparco, F; Lott, B; Lovellette, Mn; Lubrano, P; Madejski, Gm; Makeev, A; Mazziotta, Mn; Mcconville, W; Mcenery, Je; Meurer, C; Michelson, Pf; Mitthumsiri, W; Mizuno, T; Moiseev, Aa; Monte, C; Monzani, Me; Morselli, A; Moskalenko, Iv; Murgia, S; Nolan, Pl; Norris, Jp; Nuss, E; Ohsugi, T; Omodei, N; Orlando, E; Ormes, Jf; Paneque, D; Panetta, Jh; Parent, D; Pelassa, V; Pepe, M; Persic, M; Pesce Rollins, M; Piron, F; Porter, Ta; Raino, S; Rando, R; Razzano, M; Reimer, A; Reimer, O; Reposeur, T; Ritz, S; Rochester, Ls; Rodriguez, Ay; Romani, Rw; Roth, M; Ryde, F; Sadrozinski, Hfw; Sanchez, D; Sander, A; Parkinson, Pms; Scargle, Jd; Sgro, C; Siskind, Ej; Smith, Da; Smith, Pd; Spandre, G; Spinelli, P; Strickman, Ms; Suson, Dj; Tajima, H; Takahashi, H; Takahashi, T; Tanaka, T; Thayer, Jb; Thayer, Jg; Thompson, Dj; Tibaldo, L; Torres, Df; Tosti, G; Tramacere, A; Uchiyama, Y; Usher, Tl; Vasileiou, V; Vilchez, N; Villata, M; Vitale, V; Waite, Ap; Wang, P; Winer, Bl; Wood, Ks; Ylinen, T; Ziegler, M.. - In: THE ASTROPHYSICAL JOURNAL. - ISSN 0004-637X. - ELETTRONICO. - 710:2(2010), pp. 1271-1285. [10.1088/0004-637X/710/2/1271]
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11589/2011
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