English
Related papers

Related papers: Gamma-ray Clues to the Relativistic Jet Dichotomy

200 papers

If the emission of gamma-ray bursts were due to the synchrotron process in the standard internal shock scenario, then the typical observed spectrum should have a slope F(nu) \propto nu^{-1/2}, which strongly conflicts with the much harder…

Astrophysics · Physics 2009-10-31 Gabriele Ghisellini , Annalisa Celotti , Davide Lazzati

Extreme high-synchrotron peaked blazars (EHSPs) are rare high-energy sources characterised by synchrotron peaks beyond 10$^{17}$ Hz in their spectral energy distributions (SEDs). Their extreme properties challenge conventional blazar…

High Energy Astrophysical Phenomena · Physics 2025-08-26 M. Láinez , M. Nievas-Rosillo , A. Domínguez , J. L. Contreras , J. Becerra González , A. Dinesh , V. S. Paliya

The emission mechanism of the gamma-ray bursts (GRBs) is still a matter of debates. The standard synchrotron energy spectrum of cooling electrons F_E ~ E^{-1/2} is much too soft to account for the majority of the observed spectral slopes.…

Astrophysics · Physics 2009-11-10 Boris E. Stern , Juri Poutanen

We use published data on the power and production efficiency of jets in blazars with double radio lobes in order to compare results obtained using different methods. In order to eliminate selection effects, we use cross-matched sub-samples…

High Energy Astrophysical Phenomena · Physics 2016-12-28 Patryk Pjanka , Andrzej A. Zdziarski , Marek Sikora

A puzzling feature of the {\it Chandra}--detected quasar jets is that their X-ray emission decreases faster along the jet than their radio emission, resulting to an outward increasing radio to X-ray ratio. In some sources this behavior is…

Astrophysics · Physics 2016-08-30 Markos Georganopoulos , Demosthenes Kazanas

We present an interpretation of the phenomenological relations between the spectral peak, isotropic luminosity and duration of long gamma ray bursts that have been discovered by Amati et al., Ghirlanda et al., Firmani et al., and Liang &…

Astrophysics · Physics 2010-11-11 C. Thompson , P. Meszaros , M. J. Rees

We present average R-band optopolarimetric data, as well as variability parameters, from the first and second RoboPol observing season. We investigate whether gamma- ray--loud and gamma-ray--quiet blazars exhibit systematic differences in…

We find that energy losses due to synchrotron self-Compton (SSC) emission in blazar jets can produce distinctive signatures in the time-averaged synchrotron and SSC spectra of these objects. For a fairly broad range of particle injection…

Astrophysics · Physics 2009-11-07 James Chiang , Markus Boettcher

Blazars, a subclass of radio-loud active galactic nuclei with relativistic jets aligned close to our line of sight, emit highly variable non-thermal radiation across the electromagnetic spectrum. The physical origin of their emission and…

High Energy Astrophysical Phenomena · Physics 2026-01-14 Stella Boula , Apostolos Mastichiadis , Demosthenes Kazanas

Using public \fermi LAT and \swift BAT observations, we constructed the first sample of blazars selected at both hard X-rays and gamma-rays. Studying its spectral properties, we find a luminosity dependence of the spectral slopes at both…

Cosmology and Nongalactic Astrophysics · Physics 2017-02-22 R. M. Sambruna , D. Donato , M. Ajello , L. Maraschi , the GSFC BAT Team

In this paper, we use the quasi-simultaneous spectra of Fermi bright blazars and Fermi detected narrow line Seyfert 1 (NLS1) to study the blazar sequence and inverse Compton (IC) models. I. The synchrotron peak luminosities (L_{s})…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Liang Chen , J. M. Bai

A comprehensive statistical analysis of the broadband properties of EGRET blazars is presented. This analysis includes sources identified as blazars in the Sowards-Emmerd publications. Using this sample of 122 sources, we find that there is…

Astrophysics · Physics 2009-11-13 S. D. Bloom

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…

High Energy Astrophysical Phenomena · Physics 2026-05-22 Yi Zhong , Zhujian Wan , Rui Xue , Hubing Xiao , Dingrong Xiong , Ze-Rui Wang

Blazars host the most powerful persistent relativistic conical jet -- a highly collimated anisotropic flow of material/plasma. Motivated by this, we explore the blazar's broadband spectral energy distribution (SED) in an anisotropic flow of…

High Energy Astrophysical Phenomena · Physics 2021-06-14 Nagendra Kumar , Pankaj Kushwaha

We present new BeppoSAX LECS and MECS observations, covering the energy range 0.1 - 10 keV (observer's frame), of four BL Lacertae objects selected from the 1 Jy sample. All sources display a flat (alpha_x ~ 0.7) X-ray spectrum, which we…

Astrophysics · Physics 2009-11-10 P. Padovani , L. Costamante , P. Giommi , G. Ghisellini , A. Celotti , A. Wolter

We present a high resolution 1.6 GHz VSOP image of the southern blazar PKS 1921-293. The image shows a typical core-jet morphology, consistent with ground-based VLBI images. However, the addition of data from the space antenna has greatly…

Astrophysics · Physics 2015-06-24 Z. -Q. Shen , P. G. Edwards , J. E. J. Lovell , K. Fujisawa , S. Kameno , M. Inoue

In paper 1 (Cheng et al. 2001) we have shown that the soft X-ray spectra of two types of Seyfert 1 galaxies statistically vary differently with increasing intensity. In order to understand how the spectrum of blazars changes, the spectral…

Astrophysics · Physics 2017-11-01 Linpeng Cheng , Yongheng Zhao , Janyan Wei

We investigate the contribution of the beamed jet component to the high energy emission in young and compact extragalactic radio sources, focusing for the first time on the gamma-ray band. We derive predictions on the gamma-ray luminosities…

High Energy Astrophysical Phenomena · Physics 2015-06-18 Giulia Migliori , Aneta Siemiginowska , Brandon C. Kelly , Lukasz Stawarz , Annalisa Celotti , Mitchell C. Begelman

We investigate the dissipation of the bulk kinetic energy of a relativistic jet at different distances from the central power--house and analyse in detail how the dissipated energy is radiated away. We assume that the location of the…

Astrophysics · Physics 2008-11-26 K. Katarzynski , G. Ghisellini

We test different physically motivated models for the spectral shape of the $\gamma$-ray emission in a sample of 128 blazars with known redshifts detected by the Fermi Large Area Telescope (LAT) at energies above 50 GeV. The first nine…

High Energy Astrophysical Phenomena · Physics 2019-03-27 Jacobus P. van den Berg , Markus Boettcher , Alberto Dominguez , Marcos Lopez-Moya
‹ Prev 1 3 4 5 6 7 10 Next ›