Back to Search
Start Over
Radio to gamma-ray variability study of blazar S5 0716+714.
- Source :
-
Astronomy & Astrophysics / Astronomie et Astrophysique . Apr2013, Vol. 552 Issue 1, p1-24. 24p. - Publication Year :
- 2013
-
Abstract
- We present the results of a series of radio, optical, X-ray, and γ-ray observations of the BL Lac object S50716+714 carried out between April 2007 and January 2011. The multifrequency observations were obtained using several ground- and space-based facilities. The intense optical monitoring of the source reveals faster repetitive variations superimposed on a long-term variability trend on a time scale of ~350 days. Episodes of fast variability recur on time scales of ~60-70 days. The intense and simultaneous activity at optical and γ-ray frequencies favors the synchrotron self-Compton mechanism for the production of the high-energy emission. Two major low-peaking radio flares were observed during this high optical/γ-ray activity period. The radio flares are characterized by a rising and a decaying stage and agrees with the formation of a shock and its evolution. We found that the evolution of the radio flares requires a geometrical variation in addition to intrinsic variations of the source. Different estimates yield robust and self-consistent lower limits of δ ⩾ 20 and equipartition magnetic field Beq ⩾ 0.36 G. Causality arguments constrain the size of emission region ϴ ⩽ 0.004 mas. We found a significant correlation between flux variations at radio frequencies with those at optical and γ-rays. The optical/GeV flux variations lead the radio variability by ~65 days. The longer time delays between low-peaking radio outbursts and optical flares imply that optical flares are the precursors of radio ones. An orphan X-ray flare challenges the simple, one-zone emission models, rendering them too simple. Here we also describe the spectral energy distribution modeling of the source from simultaneous data taken through different activity periods. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00046361
- Volume :
- 552
- Issue :
- 1
- Database :
- Academic Search Index
- Journal :
- Astronomy & Astrophysics / Astronomie et Astrophysique
- Publication Type :
- Academic Journal
- Accession number :
- 87078580
- Full Text :
- https://doi.org/10.1051/0004-6361/201321058