相关论文: Variability Models of Gamma-Ray Blazars

Blazars exhibit multiwavelength variability, a phenomenon whose underlying mechanisms remain elusive. This study investigates the origin of such variability through leptonic blazar emission simulations, focusing on stochastic fluctuations…

We study several properties of blazars detected in the gamma-ray energy range by comparing the EGRET sources with a sample of radio blazars which can be considered possible gamma-ray candidates. We define three classes: non-gamma-ray…

EGRET has detected 67 sources associated with active galactic nuclei. With the exception of radio galaxy Cen A, all are classified as belonging to the blazar class of active galactic nuclei. The cumulative exposure from multiple EGRET…

The multi-wavelength spectral and temporal variability observed in blazars set tight constraints on current theoretical emission models. Here, we investigate the relativistic magnetic reconnection process as a source of blazar emission in…

We present the results of a new model calculation of the gamma-ray background produced by unresolved blazars, using the second EGRET catalogue and taking account of flaring. These results are compared to the preliminary gamma-ray background…

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…

Most extragalactic jets in radio-loud Active Galactic Nuclei are bright and variable gamma-ray sources, which are continuously monitored with Fermi/LAT. We present the gamma-ray properties of the MOJAVE and TANAMI AGN samples of radio-loud…

Extragalactic jets are the most powerful persistent sources of the universe. Those pointing at us are called blazars. Their relativistically boosted emission extends from radio frequencies to TeV energies. They are also suspected to be the…

Blazars are a small fraction of all extragalactic sources but, unlike other objects, they are strong emitters across the entire electromagnetic spectrum. Recent data in the microwave region of the electromagnetic spectrum have become…

Apparent evolution of relativistic flows as traced by radio emission results from a combination of several factors related to propagation of relativistic blobs or shocks, velocity, density and pressure stratification of the underlying flow,…

A model to explain variable gamma-ray sources with high-mass microblazars is described. Inverse Compton interactions between the jet of a microquasar and the UV-photon field of the stellar companion can produce high-energy gamma-rays. The…

Before the launch of the Fermi satellite only two classes of AGNs were known to produce relativistic jets and thus emit up to the gamma-ray energy range: blazars and radio galaxies, both hosted in giant elliptical galaxies. The first four…

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…

The past 20 years have seen phenomenal progress in our understanding of BL Lac objects. They form part of the blazar class, which are radio-loud AGN whose relativistic jets are aligned along our line of sight. Several critical milestones…

The observational diversity of ``gamma-ray bursts'' (GRBs) has been increasing, and the natural inclination is a proliferation of models. We explore the possibility that at least part of this diversity is a consequence of a single basic…

Blazars are beamed active galactic nuclei known for their strong multi-wavelength variability on timescales from years down to minutes. We aim to investigate the suitability of the twisting jet model presented in previous works to explain…

Blazars are a class of active galactic nuclei (AGNs) known for their very rapid variabilty in the high energy regions of the electromagnetic spectrum. Despite this known fast variability, X-ray observations have generally not revealed…

We investigate the jet morphology and kinematics of a statistically complete radio-loud AGN sample in terms of the gamma-ray properties of the sources. Gamma-ray detected AGN dominate the high end of the jet apparent speed distribution of…

We present a method to assess the reliability of the identification of EGRET sources with extragalactic radio sources. We verify that EGRET is detecting the blazar class of AGN. However, many published identifications are found to be…

The recent release of the First Fermi-LAT Source Catalog solidified the predominant association of extragalactic gamma-ray emitters to active galaxies, in particular blazars. A tight connection between AGN jet kinematics and gamma-ray…