Related papers: Internal Shocks and the Blazar Sequence
Being dominated by non-thermal (synchrotron and inverse Compton) emission from a relativistic jet, blazars offer important clues to the structure and radiative processes in extragalactic jets. Crucial information is provided by blazars'…
In the internal shock scenario for GRBs we expect some fraction of the energy of the burst to be carried by slow moving shells that were ejected at late times. These slow shells collide with faster moving outer shells when the outer shells…
4C 71.07 is a high-redshift blazar whose optical radiation is dominated by quasar-like nuclear emission. We here present the results of a spectroscopic monitoring of the source to study its unbeamed properties. We obtained 24 optical…
The fraction of a fireball kinetic kinetic energy that can be radiated away by internal shocks is sensitive to the amplitude of initial fluctuations in the fireball. We give a simple analytical description for dissipation of…
Within the standard internal shock scenario, synchrotron emission would produce a spectrum with slope F(v) proportional to v^(-1/2), as immediate consequence of the cooling timescale being shorter than the integration time. This is in…
Reinhard Schlickeiser has made groundbreaking contributions to various aspects of blazar physics, including diffusive shock acceleration, the theory of synchrotron radiation, the production of gamma-rays through Compton scattering in…
In this presentation, we report the results of intraday variability in the optical (BVRI bands) and hard X-ray band (3-79 keV) in a number of blazars. In the optical microvariability studies of the blazars S5 0716+714 and BL Lac, we…
Fast radio bursts (FRBs) can present a variety of polarization properties, and some of them have narrow spectra. We study spectral properties from perspectives of intrinsic radiation mechanisms and absorption during the waves propagating in…
The jet composition and energy dissipation mechanism of Gamma-ray bursts (GRBs) and Blazars are fundamental questions which remain not fully understood. One plausible model is to interpret the $\gamma$-ray emission of GRBs and optical…
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…
Beaming effect is important for the observational properties of blazars. In this work, we collect 91 $Fermi$ blazars with available radio Doppler factors. $\gamma$-ray Doppler factors are estimated and compared with radio Doppler factors…
Several trends have been identified in the prompt gamma-ray burst (GRB) emission: e.g. hard-to-soft evolution, pulse width evolution with energy, time lags, hardness-intensity/-fluence correlations. Recently Fermi has significantly extended…
In order to investigate the dispersion of the spectral break energy in gamma-ray bursts, we simulate internal shocks, including effects of shell-splitting after shell collisions and the Thomson optical depth due to electron--positron pairs…
The curvature of the $\gamma$-ray spectrum in blazars may reflect the intrinsic distribution of the emitting electron distribution, which will further give some information on the possible acceleration and cooling processes in the emitting…
Blazars, a unique class of active galactic nuclei, exhibit highly variable emission across the electromagnetic spectrum. This variability frequently manifests as intense flaring events, sparking an ongoing debate in recent literature about…
We revisit the blazar sequence exploiting the complete, flux limited sample of blazars with known redshift detected by the Fermi satellite after 4 years of operations (the 3LAC sample). We divide the sources into gamma-ray luminosity bins,…
Blazar emission is dominated by non-thermal radiation from a relativistic jet pointing toward us, therefore undergoing Doppler beaming. This is responsible for flux enhancement and contraction of the variability time scales, so that most…
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…
The gamma-ray emission from Flat Spectrum Radio Quasars (FSRQs), a sub-class of blazars, is believed to be generated through interactions of high-energy leptons and/or hadrons in the jet with the ambient photon fields, including those from…
We present new Gemini spectroscopical data of the Extended Emission-Line Region of 3C~305 radio galaxy in order to achieve the final answer of the long-standing question about the ionizing mechanism. The spectra show strong kinematic…