Related papers: Synchrotron-Self Compton Spectral Evolution of PKS…

The BL Lac object 1ES 0229+200 (z=0.14) has been detected by HESS during observations taking place in 2005-2006. The TeV spectrum, when corrected for the absorption of gamma-ray photons through the interaction with the extragalactic…

The spectra of BL Lac objects and Fanaroff-Riley I radio galaxies are commonly explained by the one-zone leptonic synchrotron self-Compton (SSC) model. Spectral modeling of correlated multiwavelength data gives the comoving magnetic field…

We report intensity variations of different spectral components in the BL Lac object S5 0716+714 detected during coordinated BeppoSAX and optical observations in 1996 and 1998. The transition between synchrotron and inverse Compton emission…

Aim : The nearby TeV blazar 1ES 1959+650 (z=0.047) was reported to be in flaring state during June - July 2016 by Fermi-LAT, FACT, MAGIC and VERITAS collaborations. We studied the spectral energy distributions (SEDs) in different states of…

We present the results of a multi-wavelength study of a population of X-ray bright ($\rm log(F_{0.2-12 \ keV})>-12.5$), non-$\gamma$-ray detected high and extreme high synchrotron peak (HSP, EHSP; $\rm log(\nu_{\rm peak,\ Hz})>16$) BL Lacs…

The detection of the high-frequency peaked BL Lac object (HBL) SHBL J001355.9-185406 ($z$=0.095) at high (HE; 100 MeV$<$E$<$300 GeV) and very high-energy (VHE; $E>100\,{\rm GeV}$) with the \fer\ Large Area Telescope (LAT) and the High…

Blazars are characterized by rapid variability at virtually all wavelengths from radio through TeV gamma-rays. The challenge since their discovery has been to understand the origin of their luminous, apparently nonthermal, nuclear emission.…

The high energy peaked BL Lac (HBL) object 1ES 0414+009 (z=0.287) is a distant very high-energy (VHE, E > 100 GeV) blazars with well-determined redshift. This source was detected with the High Energy Stereoscopic System (H.E.S.S.) between…

We present the results of a series of Swift and quasi simultaneous ground-based infra-red observations of the blazar 3C 454.3 carried out in April-May 2005 when the source was 10 to 30 times brighter than previously observed. We found 3C…

Synchrotron radiation from a decelerating blastwave is a widely accepted model of radio to X-ray afterglow emission from gamma-ray bursts (GRBs). GeV gamma-ray emission detected by the Fermi Large Area Telescope (LAT) and the duration of…

At the end of March 2004, the blazar S5 0716+714 underwent an optical outburst that prompted for quasi-simultaneous target-of-opportunity observations with the INTEGRAL and XMM-Newton satellites. In this paper, we report the results of the…

We report on a long-lasting, elevated gamma-ray flux state from VER J0521+211 observed by VERITAS, MAGIC, and Fermi-LAT in 2013 and 2014. The peak integral flux above 200 GeV measured with the nightly-binned light curve is $(8.8 \pm 0.4)…

Blazars host the most powerful persistent relativistic conical jet -- a highly collimated anisotropic flow of material/plasma. Motivated by this, we explore the blazar's broadband spectral energy distribution (SED) in an anisotropic flow of…

[abridged] We present results of modeling the SED and multiwavelength variability of the bright FSRQ PKS1510-089 with our time-dependent multizone Monte Carlo/Fokker-Planck code (Chen et al. 2001). As primary source of seed photons for…

We present the analysis of archival data from ROSAT and ASCA of a serendipitous BL Lac object PKS 2316-423. Because of its featureless non-thermal radio/optical continuum, PKS 2316-423 has been called as a BL Lac candidate in the…

We investigate the evolution of spectral energy distribution (SED) and underlying electron energy distribution (EED) by modeling the nearly simultaneous broadband spectra of selected bright 4FGL blazars, in the context of a combined cooling…

The blazar 1ES 0229+200 is a high frequency peaked BL Lac object with a hard TeV spectrum extending to 10 TeV. Its unusual spectral characteristics make it a frequently used probe for intergalactic radiation and magnetic fields. With new,…

PKS 2155--304 is one of the brightest blazars in the X-ray band. It was repeatedly monitored with BeppoSax during three long campaigns of about 2 days each in November of 1996, 1997 and 1999. The source underwent different states of…

Using multi-frequency spectra from TeV blazars in quiescent states, we obtain the physical parameters of the emission region of blazars within the framework of the one-zone synchrotron self-Compton (SSC) model. We numerically calculate the…

We present long-term multiwavelength observations of blazar CTA 102 ($z=1.037$). Detailed temporal and spectral analyses of $\gamma$-ray, X-ray and UV/optical data observed by {\it Fermi}-LAT, Swift XRT, NuSTAR and Swift-UVOT over a period…