Related papers: Broadband Modelling of Orphan Gamma Ray Flares

The spectral energy distribution and variability of several blazars (Mkn 501, 1 ES 2344+51.4, PKS 2155-30.4, 1 ES 1218+30.4, 3C 454.3) along the blazar sequence is investigated using a selfconsistent and timedependent lepto-hadronic hybrid…

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…

Many luminous blazars which are associated with quasar-type active galactic nuclei display broad-band spectra characterized by a large luminosity ratio of their high-energy (gamma-ray) and low-energy (synchrotron) spectral components. This…

We present the temporal and spectral study of blazar PKS 0208-512, using recent flaring activity from November 2019 to May 2020, as detected by the Fermi-LAT observatory. The contemporaneous X-ray, optical/UV observations from…

A study of blazar PKS 1424-418 was carried out using multi waveband data collected by Fermi-LAT, Swift-XRT, Swift-UVOT and SMARTS telescopes between MJD 56000 to MJD 56600 (14 Mar 2012 to 4 Nov 2013). Two flaring episodes were identified by…

Violent multi-wavelength variabilities are observed in gamma-ray-selected blazars. We present an analysis of long-term light curves for eight bright blazars to explore the co-variation pattern in the gamma-ray and radio bands. We extract…

In this paper we extend our approach to modeling multifrequency emission variability from blazars to include external-radiation Compton (ERC) emission and electron energy losses from inverse Compton scattering of seed photons originating…

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 first one started in 2012 July 16 (MJD 56124) and the second one in 2013 April 9 (MJD 56391). The multiwavelength data analysis shows that the $\gamma$-ray flare observed in 2012 was not detected in the hard-X ray bands. This result is…

In this review, recent progress in theoretical models for blazar emission will be summarized. The salient features of both leptonic and lepto-hadronic approaches to modeling blazar spectral energy distributions will be reviewed. I will…

We present a multi-wavelength study of four high redshift blazars, S5 0014+81 ($z=3.37$), CGRaBS J0225+1846 ($z=2.69$), BZQ J1430+4205 ($z=4.72$), and 3FGL J1656.2$-$3303 ($z=2.40$), using the quasi-simultaneous data from {\it Swift}, {\it…

We report the results of a multi-band observing campaign on the famous blazar 3C 279 conducted during a phase of increased activity from 2013 December to 2014 April, including first observations of it with NuSTAR. The $\gamma$-ray emission…

Very-high-energy gamma-ray flares of TeV blazars are generally accompanied by simultaneous flaring activity in X-rays. The recent observations by the Whipple collaboration of an ``orphan'' TeV flare of 1ES 1959+650 (without simultaneous…

We present a detailed temporal and spectral analysis of the blazar S5\,1044+71 using multi-wavelength data obtained from the \emph{Fermi}-LAT and Swift-XRT/UVOT telescopes. Applying the Bayesian block algorithm to the 3-day binned…

The blazar 4C 31.03 recently underwent a major gamma-ray outburst at the beginning of 2023 after a prolonged quiescent phase. Fermi-LAT reported a daily average flux of 5x10^-6 phs cm^-2 s^-1, which is about 60 times its average value. We…

We analyze the shock-in-jet models for the gamma-ray flaring blazars 0420-014, OJ 287, and 1156+295 presented in Aller et al. (2014, Paper I), quantifying how well the modeling constrains internal properties of the flow (low energy spectral…

The blazars 3C 454.3, PKS 0537-441 and PKS 2155-304 are traditionally known to be among the most active sources of this class. They emit at all frequencies, up to the gamma-rays, and are good probes of multiwavelength nuclear variability.…

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 present time-resolved broad-band observations of the quasar 3C 279 obtained from multi-wavelength campaigns conducted during the first two years of the Fermi Gamma-ray Space Telescope mission. While investigating the previously reported…

We model light curves of flares observed in blazars, assuming that they are produced by relativistic electrons/positrons injected by forward-reverse shocks traveling down the jet with relativistic speeds. We approximate the radiating region…