Related papers: Flaring Patterns in Blazars

Blazars are a rare class of active galactic nuclei (AGN) with relativistic jets pointing towards the observer. Jets are thought to be launched as Poynting-flux dominated outflows that accelerate to relativistic speeds at the expense of the…

The recent detection of very high energy (VHE) emissions from flat spectrum radio quasars (FSRQs) at high redshifts has revealed that the universe is more transparent to VHE $\gamma$-rays than it was expected. It has also questioned 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…

The flat-spectrum radio quasar 3C 345 has been showing gamma-ray activity since the mid-2000s along with activity across the electromagnetic spectrum. A gamma-ray burst in 2009 was successfully linked to relativistic outflow in 43 GHz VLBI…

Based on the classical unification, blazars, namely BL Lacertae objects (BL Lacs) and flat-spectrum radio quasars (FSRQs), are believed to correspond with radio galaxies when observed at small jet viewing angles. In this paper, we aim to…

We study the synchrotron flaring behaviour of the blazar 3C279 based on an extensive dataset covering 10 years of monitoring at 19 different frequencies in the radio-to-optical range. The properties of a typical outburst are derived from…

The observed spectra of blazars, their intrinsic emission, and the underlying populations of radiating particles are intimately related. The use of these sources as probes of the extragalactic infrared background, a prospect propelled by…

Blazars are very broadband cosmic sources with spectra spanning over twenty orders of magnitude in frequency, down to the 100 MHz regime in the radio range, up to VHE at several tens of TeV. The modelling of their spectral energy…

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 Flat Spectrum Radio Quasar PMN J2345-1555 is a bright gamma-ray source, that recently underwent a flaring episode in the IR, UV and gamma-ray bands. The flux changed quasi simultaneously at different frequencies, suggesting that it was…

We locate the gamma-ray and lower frequency emission in flares of the BL Lac object AO 0235+164 at >12pc in the jet of the source from the central engine. We employ time-dependent multi-spectral-range flux and linear polarization monitoring…

We present the results of an extensive analysis of the optical, ultraviolet, X-ray and $\gamma$-ray data collected from the observations of the BL Lac objects prototype BL Lacertae carried out over a period of nearly 13 years, between…

The flat-spectrum radio quasar 4C $+$71.07 is a high-redshift ($z=2.172$), $\gamma$-loud blazar whose optical emission is dominated by the thermal radiation from accretion disc. 4C $+$71.07 has been detected in outburst twice by the AGILE…

Flat spectrum radio quasars (FSRQs) are the most luminous blazars at GeV energies, but only rarely emit detectable fluxes of TeV gamma rays, typically during bright GeV flares. We explore the gamma-ray variability and spectral…

We examine the coincidence of times of high $\gamma$-ray flux and ejections of superluminal components from the core in EGRET blazars based on a VLBA monitoring program at 22 and 43 GHz from November 1993 to July 1997. In 23 cases of…

We report simultaneous observations at different energy bands in radio, optical, UV, X-rays and $\gamma$ rays of the flat-spectrum radio-quasar 3C 345. We built the light curve of the source at different frequencies from 2008, the beginning…

Blazars outburst provide an opportunity to study their spectral behaviour, correlated variations, and structure of the jet. Such an unprecedented flaring activity in FSRQ CTA102, during 2016 - 2017, is used for a detailed study to…

Flat spectrum radio quasars (FSRQs) are a particular class of blazars rich of optical/ultraviolet photons inside the broad line region (BLR), necessarily implying a huge optical depth for $\gamma$ rays above 20 GeV. As a consequence,…

Blazars are a sub-category of radio-loud active galactic nuclei with relativistic jets pointing towards to the observer. They are well-known for their non-thermal variable emission, which practically extends over the whole electromagnetic…

The new high energy data coming mainly from the Fermi and Swift satellites and from the ground based Cerenkov telescopes are making possible to study not only the energetics of blazar jets, but also their connection to the associated…