Related papers: On the Viewing Angle Dependence of Blazar Variabil…
A monochromatic linear source of light is rotated with certain angular frequency and when such light is analysed after reflection then a change of frequency or wavelength may be observed depending on the location of the observer. This…
We investigate the dependence of gamma-ray brightness of blazars on intrinsic properties of their parsec-scale radio jets and the implication for relativistic beaming. By combining apparent jet speeds derived from high-resolution VLBA…
The contribution of interference effects to the radiation of a charged particle moving in a medium of randomly spaced plates is considered. In the angular dependent radiation intensity a peak appears at angles $\theta\sim\pi-\gamma^{-1}$,…
The radiation observed by blazars is believed to originate from the transformation of bulk kinetic energy of relativistic jets into random energy. A simple way to achieve this is to have an intermittent central power source, producing…
Unsteady activity of gamma-ray burst sources leads to internal shocks in their emergent relativistic wind. We study the emission spectra from such shocks, assuming that they produce a power-law distribution of relativistic electrons and…
It is widely accepted that strong and variable radiation detected over all accessible energy bands in a number of active galaxies arises from a relativistic, Doppler-boosted jet pointing close to our line of sight. The size of the emitting…
With their jet pointing towards us, blazars are ideal tools to study the physics and structure of extragalactic jets. Their powerful jets are cosmic particle accelerators and are alleged to be one of the production sites of the high-energy…
The dependence of macroscopic radiation pressure on the velocity of the object being pushed is commonly attributed to the Doppler effect. This need not be the case, and here we highlight velocity dependent radiation pressure terms that have…
The frequency shift of spectral lines from astronomical objects is most often explained by the Doppler Effect arising in relative motion and the broadening of a particular line is supposed to depend on the absolute temperature, pressure or…
The polarization signatures of the blazar emissions are known to be highly variable. In addition to small fluctuations of the polarization angle around a mean value, sometimes large (> 180^o) polarization angle swings are observed. We…
Blazars are highly variable active galactic nuclei which emit radiation at all wavelengths from radio to gamma-rays. Polarized radiation from blazars is one key piece of evidence for synchrotron radiation at low energies and it also varies…
Blazars are known to emit a broad band emission from radio to gamma-rays with rapid time variations, particularly, in X- and gamma-rays. Synchrotron radiation and inverse Compton scattering are thought to play an important role in emission…
We examine the effect of Compton drag on the dynamics of a relativistic shock wave. Similarity solutions describing a radiation-supported shock are obtained for certain profiles of the external radiation intensity and the density of the…
We show that there is no universal law describing how the spectra and luminosity of synchrotron and inverse Compton radiation from relativistic jets change with increasing observation angle. Instead, the physics of particle acceleration…
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…
The influence of the Doppler effect in the fireball framework on the spectrum of gamma-ray bursts is investigated. The study shows that the shape of the expected spectrum of an expanding fireball remains almost the same as that of the…
Extremely strong magnetic fields change the vacuum index of refraction. Although this polarization dependent effect is small for typical neutron stars, it is large enough to decouple the polarization states of photons traveling within the…
The optical radiation and polarization signatures in blazars are known to be highly variable during flaring activities. It is frequently argued that shocks are the main driver of the flaring events. However, the spectral variability…
The new results of the evolution of the synchrotron peak for Mrk 421 are mostly likely related to the particle acceleration process. In order to account for the above results, we present a model of blazar variability during the flare in…
The spectral characteristics of the pulsed gamma-ray emission from outer-magnetospheric particle accelerators are investigated. Either positrons or electrons are accelerated outwards by the magnetic-field-aligned electric field to emit…