naa a22 4500 510732348 CHVBK 20180411082957.0 cr unu---uuuuu 180411e20131001xx s 000 0 eng 10.1134/S106377291310003X doi (NATIONALLICENCE)springer-10.1134/S106377291310003X Variability of the blazar 3C 454.3 during 2007-2010 [Elektronische Daten] [V. Hagen-Thorn, V. Larionov, D. Blinov, A. Arkharov, E. Hagen-Thorn, E. Borisova, L. Takalo, A. Sillanpää] Results are presented of multicolor observations of the blazar 3C 454.3 carried out at the Astronomical Institute of St. Petersburg State University and the Central Astronomical Observatory of the Russian Academy of Sciences in 2007-2010. The color variability of the blazar is analyzed. Several outbursts were observed. The existence of two variable synchrotron sources is inferred. The first is responsible for the small-amplitude flux variability, and the second for flares. In each flare, the relative spectral energy distribution (SED) of the variable source is found to be constant. All the SEDs are power laws, but with different spectral indexes in different flares. This indicates the impossibility of explaining the global variability only via a difference in Doppler boosting due to variations of the angle between the line of sight and the velocity of the electrons responsible for the synchrotron radiation. The polarimetric and photometric observations are used to derive the absolute SED of constant component. A comparison of the observed SEDs for different brightness levels with the SED of the constant componentmakes it possible to explain the observed color variability as due to the superposition of a bluer variable source with a constant SED and variable flux onto the constant component. Pleiades Publishing, Ltd., 2013 Hagen-Thorn V. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut Larionov V. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut Blinov D. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut Arkharov A. Central (Pulkovo) Astronomical Observatory, Russian Academy of Sciences, Saint Petersburg, Russia aut Hagen-Thorn E. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut Borisova E. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut Takalo L. Tuorla Observatory, University of Turku, Turku, Finland aut Sillanpää A. Tuorla Observatory, University of Turku, Turku, Finland aut Astronomy Reports Springer US; http://www.springer-ny.com 57/10(2013-10-01), 726-733 1063-7729 57:10<726 2013 57 11444 https://doi.org/10.1134/S106377291310003X text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1134/S106377291310003X text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Hagen-Thorn V. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut NATIONALLICENCE 700 1- Larionov V. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut NATIONALLICENCE 700 1- Blinov D. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut NATIONALLICENCE 700 1- Arkharov A. Central (Pulkovo) Astronomical Observatory, Russian Academy of Sciences, Saint Petersburg, Russia aut NATIONALLICENCE 700 1- Hagen-Thorn E. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut NATIONALLICENCE 700 1- Borisova E. Sobolev Astronomical Institute, Saint Petersburg State University, Saint Petersburg, Russia aut NATIONALLICENCE 700 1- Takalo L. Tuorla Observatory, University of Turku, Turku, Finland aut NATIONALLICENCE 700 1- Sillanpää A. Tuorla Observatory, University of Turku, Turku, Finland aut NATIONALLICENCE 773 0- Astronomy Reports Springer US; http://www.springer-ny.com 57/10(2013-10-01), 726-733 1063-7729 57:10<726 2013 57 11444 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer