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COMPREHENSIVE MONITORING OF GAMMA-RAY BRIGHT BLAZARS. I. STATISTICAL STUDY OF OPTICAL, X-RAY, AND GAMMA-RAY SPECTRAL SLOPES.

Authors :
Williamson, Karen E.
Jorstad, Svetlana G.
Marscher, Alan P.
Larionov, Valeri M.
Smith, Paul S.
Agudo, Iván
Arkharov, Arkady A.
Blinov, Dmitry A.
Casadio, Carolina
Efimova, Natalia V.
Gómez, José L.
Hagen-Thorn, Vladimir A.
Joshi, Manasvita
Konstantinova, Tatiana S.
Kopatskaya, Evgenia N.
Larionova, Elena G.
Larionova, Liudmilla V.
Malmrose, Michael P.
McHardy, Ian M.
Molina, Sol N.
Source :
Astrophysical Journal. 7/10/2014, Vol. 789 Issue 2, p1-1. 1p.
Publication Year :
2014

Abstract

We present γ-ray, X-ray, ultraviolet, optical, and near-infrared light curves of 33 γ-ray bright blazars over 4 years that we have been monitoring since 2008 August with multiple optical, ground-based telescopes and the Swift satellite, and augmented by data from the Fermi Gamma-ray Space Telescope and other publicly available data from Swift. The sample consists of 21 flat-spectrum radio quasars (FSRQs) and 12 BL Lac objects (BL Lacs). We identify quiescent and active states of the sources based on their γ-ray behavior. We derive γ-ray, X-ray, and optical spectral indices, αγ, αX, and αo, respectively (Fν∝να), and construct spectral energy distributions during quiescent and active states. We analyze the relationships between different spectral indices, blazar classes, and activity states. We find (1) significantly steeper γ-ray spectra of FSRQs than for BL Lacs during quiescent states, but a flattening of the spectra for FSRQs during active states while the BL Lacs show no significant change; (2) a small difference of αX within each class between states, with BL Lac X-ray spectra significantly steeper than in FSRQs; (3) a highly peaked distribution of X-ray spectral slopes of FSRQs at ∼ –0.60, but a very broad distribution of αX of BL Lacs during active states; (4) flattening of the optical spectra of FSRQs during quiescent states, but no statistically significant change of αo of BL Lacs between states; and (5) a positive correlation between optical and γ-ray spectral slopes of BL Lacs, with similar values of the slopes. We discuss the findings with respect to the relative prominence of different components of high-energy and optical emission as the flux state changes. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
0004637X
Volume :
789
Issue :
2
Database :
Academic Search Index
Journal :
Astrophysical Journal
Publication Type :
Academic Journal
Accession number :
96773262
Full Text :
https://doi.org/10.1088/0004-637X/789/2/135