Synchrotron self-compton model for rapid nonthermal flares in blazars with frequency-dependent time lags

被引:144
作者
Sokolov, A
Marscher, AP
McHardy, IM
机构
[1] Boston Univ, Dept Astron, Boston, MA 02215 USA
[2] Univ Southampton, Dept Phys & Astron, Southampton SO17 1BJ, Hants, England
关键词
galaxies : active; galaxies : jets; quasars : individual (3C 273); radiation mechanisms : nonthermal; radiative transfer; shock waves;
D O I
10.1086/423165
中图分类号
P1 [天文学];
学科分类号
0704 ;
摘要
We model rapid variability of multifrequency emission from blazars occurring across the electromagnetic spectrum ( from radio to gamma rays). Lower energy emission is produced by the synchrotron mechanism, whereas higher energy emission is due to inverse Compton scattering of the synchrotron emission. We take into account energy stratification established by particle acceleration at shock fronts and energy losses due to synchrotron emission. We also consider the effect of light-travel delays for the synchrotron emission that supplies the seed photons for inverse Compton scattering. The production of a flare is caused by the collision between a relativistic shock wave and a stationary feature in the jet (e.g., a Mach disk). The collision leads to the formation of forward and reverse shocks, which confine two contiguous emission regions resulting in complex profiles of simulated flares. Simulations of multifrequency flares indicate that relative delays between the inverse Compton flares and their synchrotron counterparts are dominated by energy stratification and geometry of the emitting regions, resulting in both negative and positive time delays depending on the frequency of observation. Light-travel effects of the seed photons may lead to a noticeable delay of the inverse Compton emission with respect to synchrotron variability if the line of sight is almost perfectly aligned with the jet. We apply the model to a flare in 3C 273 and derive the properties of shocked plasma responsible for the flare. We show that the pronounced negative time delay between the X-ray and IR light curves (X-rays peak after the maximum in the synchrotron emission) can be accounted for if both forward and reverse shocks are considered.
引用
收藏
页码:725 / 746
页数:22
相关论文
共 40 条
[1]   Particle acceleration by ultrarelativistic shocks: theory and simulations [J].
Achterberg, A ;
Gallant, YA ;
Kirk, JG ;
Guthmann, AW .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 2001, 328 (02) :393-408
[2]   Three-dimensional simulations of relativistic precessing jets probing the structure of superluminal sources [J].
Aloy, MA ;
Martí, JM ;
Gómez, JL ;
Agudo, N ;
Müller, E ;
Ibáñez, JM .
ASTROPHYSICAL JOURNAL, 2003, 585 (02) :L109-L112
[3]  
Anile A. M., 1989, Relativistic Fluids and Magneto-Fluids: With Applications in Astrophysics and Plasma Physics
[4]   The evolution of shocks in blazar jets [J].
Bicknell, GV ;
Wagner, SJ .
PUBLICATIONS OF THE ASTRONOMICAL SOCIETY OF AUSTRALIA, 2002, 19 (01) :129-137
[5]   RELATIVISTIC JETS AS COMPACT RADIO-SOURCES [J].
BLANDFORD, RD ;
KONIGL, A .
ASTROPHYSICAL JOURNAL, 1979, 232 (01) :34-48
[6]   Comptonization of infrared radiation from hot dust by relativistic jets in quasars [J].
Blazejowski, M ;
Sikora, M ;
Moderski, R ;
Madejski, GM .
ASTROPHYSICAL JOURNAL, 2000, 545 (01) :107-116
[7]   Rapid variability in the synchrotron self-Compton model for blazars [J].
Chiaberge, M ;
Ghisellini, G .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1999, 306 (03) :551-560
[8]   TIME-DEPENDENT MODELS OF MAGNETIZED PAIR PLASMAS [J].
COPPI, PS .
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1992, 258 (04) :657-683
[9]   Simultaneous X-ray and gamma-ray observations of TeV blazars: Testing synchro-compton emission models and probing the infrared extragalactic background [J].
Coppi, PS ;
Aharonian, FA .
ASTROPHYSICAL JOURNAL, 1999, 521 (01) :L33-L36
[10]  
Courant R., 1948, Supersonic Flow and Shock Waves