Details

Autor(en) / Beteiligte

• Rani, B.
• Krichbaum, T. P.
• Fuhrmann, L.
• Böttcher, M.
• Lott, B.
• Aller, H. D.
• Aller, M. F.
• Angelakis, E.
• Bach, U.
• Bastieri, D.
• Falcone, A. D.
• Fukazawa, Y.
• Gabanyi, K. E.
• Gupta, A. C.
• Gurwell, M.
• Itoh, R.
• Kawabata, K. S.
• Krips, M.
• Lähteenmäki, A. A.
• Liu, X.
• Marchili, N.
• Max-Moerbeck, W.
• Nestoras, I.
• Nieppola, E.
• Quintana-Lacaci, G.
• Readhead, A. C. S.
• Richards, J. L.
• Sasada, M.
• Sievers, A.
• Sokolovsky, K.
• Stroh, M.
• Tammi, J.
• Tornikoski, M.
• Uemura, M.
• Ungerechts, H.
• Urano, T.
• Zensus, J. A.

Titel

Radio to gamma-ray variability study of blazar S5 0716+714

Ist Teil von

• Astronomy and astrophysics (Berlin), 2013-04, Vol.552, p.np-np

Ort / Verlag

United States: EDP Sciences

Erscheinungsjahr

2013

Link zum Volltext

Quelle

EZB Free E-Journals

Beschreibungen/Notizen

• 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. Theoptical/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.