相关论文: A Shock-in-Jet Synchrotron Mirror Model for Blazar…
We find that energy losses due to synchrotron self-Compton (SSC) emission in blazar jets can produce distinctive signatures in the time-averaged synchrotron and SSC spectra of these objects. For a fairly broad range of particle injection…
Blazar jets are renowned for their rapid violent variability and multiwavelength flares, however, the physical processes responsible for these flares are not well understood. In this paper we develop a time-dependent inhomogeneous fluid jet…
Bright and fast gamma-ray flares with hard spectra have been recently detected from the blazar 3C 279, with apparent GeV luminosities up to $10^{49}$ erg/s. The source is observed to flicker on timescales of minutes with no comparable…
The blazar 3C 279 is well known for its rapid and large-amplitude variability. On 20 December 2013, the source exhibited an orphan {\gamma}-ray flare characterized by a flux-doubling timescale of a few hours, a very hard spectrum, a…
The radiation observed by blazars is believed to originate from the transformation of bulk kinetic energy of relativistic jets into random energy. A simple way to achieve this is to have an intermittent central power source, producing…
Blazars, a class of active galaxies whose jets are relativistic and collimated flows of plasma directed along the line of sight and are prone to a slew of magneto-hydrodynamic (MHD) instabilities. We aim to study the interplay of radiation…
We present the theoretical background and detailed equations for the synchrotron emission of a shock wave propagating in a relativistic jet. We then show how the evolution of an outburst in this shock-in-jet scenario can be analytically…
We investigate the spectral and timing signatures of the internal-shock model for blazars. For this purpose, we develop a semi-analytical model for the time-dependent radiative output from internal shocks arising from colliding relativistic…
Very fast variability on scales of minutes is regularly observed in Blazars. The assumption that these flares are emerging from the dominant emission zone of the very high energy (VHE) radiation within the jet challenges current…
We developed a multi-region radiation model for the evolution of flux and spectral index with time. In this model, each perturbation component in the jet produces an independent flare. The model can be used to study the decomposition of…
Recent multiwavelength observations of PKS 0208-512 by SMARTS, Fermi, and Swift revealed that gamma-ray and optical light curves of this flat spectrum radio quasars are highly correlated, but with an exception of one large optical flare…
Multiwavelength monitoring of the blazar 3C 279 observed a very bright, 12-hour, orphan gamma-ray flare on 20 Dec 2013 with a uniquely hard Fermi-LAT spectrum and high Compton dominance. We work with a one-zone, leptonic model with both…
We compare the rise and decay timescales of $\sim$200 long-term ($\sim$weeks-months) GeV and R-band outbursts and $\sim$25 short-term ($\sim$hr-day) GeV flares in a sample of 10 blazars using light curves from the Fermi-LAT and the…
Multiwavelength observations of blazars such as Mrk 421 and Mrk 501 show that they exhibit strong short time variabilities in flare-like phenomena. Based on the homogeneous synchrotron self-Compton (SSC) model and assuming that time…
We present a phenomenological jet model which is able to reproduce well the observed variations of the submillimetre-to-radio emission of the bright quasar 3C 273 during the last 20 years. It is a generalization of the original shock model…
Even with several thousand {\it Fermi}-LAT blazar detections, the $\gamma$-ray emission mechanism is poorly understood. We explore correlated optical/$\gamma$-ray flux variations for 178 {\it Fermi}-LAT blazars regularly monitored by KAIT,…
In blazars such as 3C 279, GeV gamma-rays are thought to be produced by inverse Compton scattering of soft photons injected from external sources into the jet. Because of the large bulk Lorentz factor of the jet, the energy of soft photons…
We describe the time-dependent radiation transfer in blazar jets, within the internal shock model. We assume that the central engine, which consists of a black hole and an accretion disk, spews out relativistic shells of plasma with…
The broadband spectrum from the 2013 December 20 $\gamma$-ray flare from 3C~279 is analyzed with our previously-developed one-zone blazar jet model. We are able to reproduce two SEDs, a quiescent and flaring state, the latter of which had…
Observations of blazar flaring states reveal remarkably different variability time scales. Especially rapid flares with flux doubling time scales of the order of minutes have been puzzling for quite some time. Many modeling attempts use the…