Related papers: What determines the observational differences of b…
Blazars are characterized by large amplitude and fast variability, indicating that the electron distribution is rapidly changing, often on time scales shorter than the light crossing time. We study the time dependent behavior of the…
In this paper: 1. The assumption of the dependence of Doppler factor on the emission frequency (Fan et al. 1993) is used to explain the observational differences between the radio-selected BL Lac objects(RBLs) and the X-Ray-Selected BL Lac…
Recent population studies have shown that the variability Doppler factors can adequately describe blazars as a population. We use the flux density variations found within the extensive radio multi-wavelength datasets of the F-GAMMA program,…
In a two-component jet model, the emissions are the sum of the core and extended emissions: $S^{\rm ob}=S_{\rm core}^{\rm ob}+S_{\rm ext}^{\rm ob}$, with the core emissions, $S_{\rm core}^{\rm ob}= f S_{\rm ext}^{\rm ob}\delta^{q}$, being a…
Blazars are characterized by large amplitude and fast variability, indicating that the electron distribution is rapidly changing, often on time scales shorter than the light crossing time. The emitting region is sufficiently compact to let…
We present a comprehensive temporal and spectral analysis of a few blazars using multi-wavelength observations. Rapid flux variations are quantified via the doubling/halving timescale method, revealing the shortest variability timescales of…
We estimate the intrinsic luminosities and synchrotron peak frequency using the derived Doppler factor for a sample of 170 BL Lac objects, of which the synchrotron peak frequency are derived by fitting the SED constructed with the collected…
In this paper we develop the extended jet model of Potter & Cotter to model the simultaneous multi-wavelength spectra of six Compton-dominant blazars. We include an accelerating parabolic base transitioning to a slowly decelerating conical…
There is growing evidence that the estimations of the beaming Doppler factor in TeV BL Lac object based on the Self Synchrotron Compton (SSC) models are in strong disagreement with those deduced from the unification models between blazars…
The BL Lac object S5 0716+71 was target of a coordinated and global multi-frequency campaign to search for rapid and correlated variability and signatures of the inverse-Compton catastrophe. Here we present first results obtained from a…
Internal shocks propagating through an ambient radiation field, are subject to a radiative drag that, under certain conditions, can significantly affect their dynamics and, consequently, the evolution of the beaming cone of emission…
Blazars show rapid and violent variabilities, which timescale are often less than a day. We studied intraday variations by applying a shot analysis technique to Kepler monitoring of blazar W2R 1926+42 in Quarter 14. We obtained a mean…
The RoboPol instrument and the relevant program was developed in order to conduct a systematic study of the optical polarisation variability of blazars. Driven by the discovery that long smooth rotations of the optical polarisation plane…
We present the results of multiband observations of the blazar S5 0716+714 intra-night variability performed during 23 nights in the period from 04.2014 through 04.2015. The bluer-when-brighter trend is detected in both intra- and…
The Fermi Gamma-Ray Space Telescope observations of blazars show a strong correlation between the spectral index of their gamma-ray spectra and their synchrotron peak frequency $\nu_{\rm{pk}}^{\rm{syn}}$; additionally, the rate of Compton…
We propose a scenario where blazars are classified as flat-spectrum radio quasars (FSRQs), BL Lacs, low synchrotron, or high synchrotron peaked objects according to a varying mix of the Doppler boosted radiation from the jet, the emission…
Multiband optical photometry data of blazar S5 0716+714 obtained from 2002 to 2019 reveal stable color index change with flux variability. We analyzed this trend under variability caused by the Doppler factor change in the presence of a…
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 fit the spectral energy distributions (SEDs) of members of a large sample of Fermi 2LAC blazars to synchrotron and inverse Compton (IC) models. Our main results are as follows. (i) As suggested by previous works, the correlation between…
Blazars' non-thermal emission shows rapid variability across all wavelengths, so spectral energy distributions (SEDs) built from quasi-simultaneous data are crucial for revealing the jets physical properties. In this work, we construct…