Radio to gamma-ray variability study of blazar S5 0716+714
Radio to gamma-ray variability study of blazar S5 0716+714
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DOI：
10.1051/0004-6361/201321058
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发表时间：
2013-01
影响因子：
6.5
通讯作者：
B. Rani;T. Krichbaum;L. Fuhrmann;M. Boettcher;B. Lott;H. Aller;M. Aller;E. Angelakis;U. Bach;D. Bastieri;A. Falcone;Y. Fukazawa;K. Gabányi;A. Gupta;M. Gurwell;R. Itoh;K. Kawabata;M. Krips;A. Lahteenmaki;X. Liu;N. Marchili;W. Max-Moerbeck;I. Nestoras;E. Nieppola;G. Quintana-Lacaci;A. Readhead;J. Richards;M. Sasada;A. Sievers;K. Sokolovsky;M. Stroh;J. Tammi;M. Tornikoski;M. Uemura;H. Ungerechts;T. Urano;J. K. M. F. Radioastronomie;H Germany;A. Institute;O. Athens;C. F. Research;North-West University;P. Campus;S. Africa;1. Universit'eBordeaux;CNRSIN2p3;Centre d'Etudes Nucl'eaires de Bordeaux Gradignan;France.;A. Department;U. Michigan;Ann Arbor Istituto Nazionale di Fisica Nucleare;Sezione di Padova;Italy.;D. Astronomia;U. Padova;D. Astronomy;Astrophysics;P. S. University;U. Park;D. Sciences;Hiroshima University;F. Observatory;Hungary.;K. Observatory;R. C. F. Astronomy;Earth Sciences;H. A. O. Sciences;Aryabhatta Research Institute of Observational Sciences-Aryabhatta-Research-Institute-of-Observational-102844814;Manora Peak;India.;H. C. F. Astrophysics;Cambridge;Hiroshima Astrophysical Science Center;Iram;300 rue de la Piscine;A. L. M. R. Observatory;Finland.;Xinjiang Astronomical Observatory;Chinese Academy of Sciences;P. China;C. 9. Astronomy;C. I. O. Technology.;Instituto de Radioastronom'ia Milim'etrica;Granada;Spain.;Cab;INTA-CSIC;C. Ajalvir;Madrid;P. University;D. Physics;D. Astronomy;Kyoto University;A. Institute;Moscow;Russia.
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文献类型：
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作者：
B. Rani;T. Krichbaum;L. Fuhrmann;M. Boettcher;B. Lott;H. Aller;M. Aller;E. Angelakis;U. Bach;D. Bastieri;A. Falcone;Y. Fukazawa;K. Gabányi;A. Gupta;M. Gurwell;R. Itoh;K. Kawabata;M. Krips;A. Lahteenmaki;X. Liu;N. Marchili;W. Max-Moerbeck;I. Nestoras;E. Nieppola;G. Quintana-Lacaci;A. Readhead;J. Richards;M. Sasada;A. Sievers;K. Sokolovsky;M. Stroh;J. Tammi;M. Tornikoski;M. Uemura;H. Ungerechts;T. Urano;J. K. M. F. Radioastronomie;H Germany;A. Institute;O. Athens;C. F. Research;North-West University;P. Campus;S. Africa;1. Universit'eBordeaux;CNRSIN2p3;Centre d'Etudes Nucl'eaires de Bordeaux Gradignan;France.;A. Department;U. Michigan;Ann Arbor Istituto Nazionale di Fisica Nucleare;Sezione di Padova;Italy.;D. Astronomia;U. Padova;D. Astronomy;Astrophysics;P. S. University;U. Park;D. Sciences;Hiroshima University;F. Observatory;Hungary.;K. Observatory;R. C. F. Astronomy;Earth Sciences;H. A. O. Sciences;Aryabhatta Research Institute of Observational Sciences-Aryabhatta-Research-Institute-of-Observational-102844814;Manora Peak;India.;H. C. F. Astrophysics;Cambridge;Hiroshima Astrophysical Science Center;Iram;300 rue de la Piscine;A. L. M. R. Observatory;Finland.;Xinjiang Astronomical Observatory;Chinese Academy of Sciences;P. China;C. 9. Astronomy;C. I. O. Technology.;Instituto de Radioastronom'ia Milim'etrica;Granada;Spain.;Cab;INTA-CSIC;C. Ajalvir;Madrid;P. University;D. Physics;D. Astronomy;Kyoto University;A. Institute;Moscow;Russia.
我们介绍了2007年4月至2011年1月期间对BL Lac天体S50716+714进行的一系列无线电、光学、X射线和γ射线观测的结果。多频观测是利用若干地面和空间设施获得的。对源的强烈光学监测显示，在20350天的时间尺度上，叠加在长期变化趋势上的重复性变化更快。快速变率的发作在60 - 70天的时间尺度上反复发生。在光学和γ射线频率下的强烈和同时的活动有利于同步加速器自康普顿机制产生高能发射。在这个高光学/γ射线活动期间，观测到两个主要的低峰值射电耀斑。射电耀斑具有上升和衰减两个阶段的特征，与激波的形成和演化相一致。我们发现，除了源的本征变化外，射电耀斑的演化还需要几何变化。不同的估计给出了稳定的和自洽的下限δ ≥ 20和均分磁场Beq ≥ 0.36 G。因果关系参数限制了发射区的大小θ ≤ 0.004 mas。我们发现，在无线电频率下的通量变化与光学和γ射线的通量变化之间存在显著的相关性。光学/GeV通量变化导致射电变率约65天。射电爆发与光学耀斑之间的延迟时间较长，说明光学耀斑是射电爆发的前兆。一个孤立的X射线耀斑挑战了简单的单区发射模型，使它们过于简单。在这里，我们还描述了光谱能量分布建模的来源，通过不同的活动期间采取的同步数据。
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.