Related papers: Emitting electrons and source activity in Markaria…
Previous studies on the fitting of spectral energy distributions (SEDs) often apply the external-Compton process to interpret the high-energy peak of low-synchrotron-peaked (LSP) BL Lac objects (LBLs), despite the lack of strong broad…
Mkn 421 was repeatedly observed with BeppoSAX in 1997-1998. The source showed a very rich phenomenology, with remarkable spectral variability. This is the second of two papers presenting the results of a thorough temporal and spectral…
The phenomenology of gamma-ray bright blazars can be accounted for by a sequence in the source power and intensity of the diffuse radiation field surrounding the relativistic jet. Correspondingly, the equilibrium particle distribution peaks…
We present an extensive analysis of the multi-wavelength data of the low-synchrotron-peaked BL Lac object CGRaBS J0211+1051, which has been gathered over more than ten years with many observatories. Two major gamma-ray flares have been…
We study the synchrotron component of the spectral energy distribution (SED) on the sample of 877 blazars using the ASDC SED Builder Tool with available broadband data from the literature. Our sample includes 423 flat-spectrum radio sources…
We have observed Markarian 501 in Very High Energy (VHE) gamma-ray wavelength band for 70.6 hours from 15 April to 30 May, 2012 using TACTIC telescope. Detailed analysis of $\sim$66.3 hours of clean data revealed the presence of a TeV…
Evidence for very hard, intrinsic $\gamma$-ray source spectra, as inferred after correction for absorption in the extragalactic background light (EBL), has interesting implications for the acceleration and radiation mechanisms acting in…
There are still some important unanswered questions about the detailed particle acceleration and escape occurring during the quiescent epoches. As a result, the particle distribution that is adopted in the blazar quiescent spectral model…
The broadband spectrum of a BL Lac object, OJ 287, from radio to $\gamma$-rays obtained during a major $\gamma$-ray flare detected by \emph{Fermi} in 2009 are studied to understand the high energy emission mechanism during this episode.…
In this work we investigate the nature of multi-wavelength variability of blazars from a purely numerical approach. We use a time-dependent one-zone leptonic blazar emission model to simulate multi-wavelength variability by introducing…
We present a detailed characterisation and theoretical interpretation of the broadband emission of the paradigmatic TeV blazar Mrk 421, with special focus on the multi-band flux correlations. The dataset has been collected through an…
We carried a detailed temporal and spectral study of the BL\,Lac by using the long-term \emph{Fermi}-LAT and \emph{Swift}-XRT/UVOT observations, during the period MJD\,59000-59943. The daily-binned $\gamma$-ray light curve displays a…
A microscopic calculation of Compton scattering on the nucleon is presented which encompasses the lowest energies -- yielding nucleon polarizabilities -- and extends to energies of the order of 600 MeV. We have used the covariant "Dressed…
Blazars, a subclass of radio-loud active galactic nuclei with relativistic jets aligned close to our line of sight, emit highly variable non-thermal radiation across the electromagnetic spectrum. The physical origin of their emission and…
This work is a summary of the X-ray spectral studies of 29 TeV $\gamma$-ray emitting blazars observed with Swift/XRT, especially focusing on sources for which X-ray regime allows to study the low and the high energy ends of the particle…
S5 0716+714 is a typical BL Lacertae object. In this paper we present the analysis and results of long term simultaneous observations in the radio, near-infrared, optical, X-ray and $\gamma$-ray bands, together with our own photometric…
Mrk421 displayed its highest flux state ever observed in February of 2010 with very high TeV fluxes and interesting cross-band correlations and a spectral energy distribution (SED) evolution not entirely consistent with the standard single…
We address the question of why low-luminosity radio sources with similar flat radio spectra show a range of optical activity. The investigation is based on the spectral energy distributions (SEDs) of objects from the 200 mJy sample. We…
We present two BeppoSAX observations of BL Lacertae as part of a multiwavelength radio-to-TeV campaign. During the first observation we observe a faint Compton spectrum, while during the second, we detect a synchrotron spectrum with the…
We discuss the correlation between the evolution of the TeV emission and X-ray radiation observed in high-energy peaked BL Lac objects. We describe such a correlation by a simple power law. In the first part of this work we present…