相关论文: Blazar flares from plasma blobs crossing the broad…
The blazar 3C 279 is well known for its prolific emission of rapid flares. A particular event occurred on 12/20/2013, exhibiting a large flux increase with a doubling time scale of a few hours, a very hard gamma-ray spectrum, and a…
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…
Blazars, a class of highly variable active galactic nuclei, sometimes exhibit Orphan $\gamma$-ray flares. These flares having high flux only in $\gamma$-ray energies do not show significant variations in flux at lower energies. We study the…
Blazars are a class of active galactic nuclei which host relativistic jets oriented close to the observer's line of sight. Blazars have very complex variability properties. Flares, namely flux variations around the mean value with a…
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…
Blazars radiate from relativistic plasma jets with bulk Lorentz factors {\Gamma} ~ 10, closely aligned along our line of sight. In a number of blazars of the Flat Spectrum Radio Quasar type such as 3C 454.3 and 3C 279 gamma-ray flares have…
Blazars exhibit flares across the electromagnetic spectrum. Many $\gamma$-ray flares are highly correlated with flares detected at optical wavelengths; however, a small subset appears to occur in isolation, with little or no variability…
Characterisation of the long-term variations in the broad line region in a luminous blazar, where Comptonisation of broad-line emission within a relativistic jet is the standard scenario for production of gamma-ray emission that dominates…
Recently, blazar 4C +27.50 was found to be flaring in gamma-rays since its detection with Fermi-LAT in 2008. For the first time, a dedicated temporal and spectral study of the blazar 4C +27.50 has been performed in this work to understand…
Jets in blazars are an excellent forum for studying acceleration at relativistic shocks using the highly-variable emission seen across the electromagnetic spectrum. Our recent work on combining multi-wavelength leptonic emission models with…
The well studied blazar 3C 279 underwent a giant $\gamma$-ray outburst in 2014 March-April. The measured $\gamma$-ray flux (1.21 $\pm$ 0.10 $\times$ 10$^{-5}$ ph cm$^{-2}$ s$^{-1}$ in 0.1-300 GeV energy range) is the highest detected from…
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…
Blazars are strongly variable sources that occasionally show spectacular flares visible in various energy bands. These flares are often, but not always, correlated. In a number of cases the peaks of optical flares are found to be somewhat…
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,…
Using blazar light curves from the optical All-Sky Automated Survey for Supernovae (ASAS-SN) and the $\gamma$-ray \textit{Fermi}-LAT telescope, we performed the most extensive statistical correlation study between both bands, using a sample…
Blazars exhibit flares across the entire electromagnetic spectrum. Many $\gamma$-ray flares are highly correlated with flares detected at longer wavelengths; however, a small subset appears to occur in isolation, with little or no…
We present a new time-dependent leptonic code that we developed to model the varying multi-wavelength (MWL) emission during blazar flares. In our modeling, we assume that the blazar emission originates from a plasma blob located in the jet,…
Blazars show optical and $\gamma$-ray flux variations that are generally correlated, although there are exceptions. Here we present anomalous behaviour seen in the blazar 3C 454.3 based on an analysis of quasi-simultaneous data at optical,…
Blazars emit a highly-variable non-thermal spectrum. It is usually assumed that the same non-thermal electrons are responsible for the IR-optical-UV emission (via synchrotron) and the gamma-ray emission (via inverse Compton). Hence, the…
Comprehensive VLBI and multi-waveband monitoring indicate that a single superluminal knot can cause a number of gamma-ray flares at different locations. However, the often very rapid variability timescale is a challenge to theoretical…