Results 81 to 90 of about 38,287 (310)
Doppler Factor Estimation for Fermi Blazars
Astrophysical Journal, 2020 In this work, we exploit the luminosity of the broad-line region (BLR) for 50 Fermi blazars through matching the coordinates between the Sloan Digital Sky Survey catalog, Fermi Large Area Telescope Third Source Catalog, and the Fermi Large Area Telescope
Lixia Zhang +4 more
semanticscholar +1 more source
Constraining the Limiting Brightness Temperature and Doppler Factors for the Largest Sample of Radio-bright Blazars [PDF]
Astrophysical Journal, 2018 Relativistic effects dominate the emission of blazar jets, complicating our understanding of their intrinsic properties. Although many methods have been proposed to account for them, the variability Doppler factor method has been shown to describe the ...
I. Liodakis +5 more
semanticscholar +1 more source
BL Lac Contribution to the Extragalactic Gamma-Ray Background [PDF]
, 2007 Very high energy gamma-rays from blazars traversing cosmological distances through the metagalactic radiation field can convert into electron-positron pairs in photon-photon collisions. The converted gamma-rays initiate electromagnetic cascades driven by
Aharonian +37 more
core +2 more sources
Blazars at Very High Energies: Emission Modelling
Galaxies, 2022 Blazars are very broadband cosmic sources with spectra spanning over twenty orders of magnitude in frequency, down to the 100 MHz regime in the radio range, up to VHE at several tens of TeV.
Hélène Sol, Andreas Zech
doaj +1 more source
A model for periodic blazars [PDF]
Monthly Notices of the Royal Astronomical Society, 2016 We describe a scenario to explain blazar periodicities with timescales of $\sim$ few years. The scenario is based on a binary super-massive black hole (SMBH) system in which one of the two SMBH carries a jet. We discuss the various mechanisms that can cause the jet to precess and produce corkscrew patterns through space with a scale of $\sim$ few pc ...
Antonio Stamerra +3 more
openaire +4 more sources
Estimating black hole masses of blazars [PDF]
, 2010 Estimating black hole masses of blazars is still a big challenge. Because of the contamination of jets, using the previously suggested size -- continuum luminosity relation can overestimate the broad line region (BLR) size and black hole mass for radio ...
BM Peterson +23 more
core +1 more source
The Fermi blazar sequence [PDF]
Monthly Notices of the Royal Astronomical Society, 2017 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, collect all the archival data for all blazars, and construct their spectral energy distribution (SED). We describe
Gabriele Ghisellini +4 more
openaire +4 more sources
On the intrinsic shape of gamma-ray spectrum for Fermi blazars
, 2018 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 region.
Dong, Ai-Jun +10 more
core +1 more source
Astroparticle Physics, 1999 TeV emission can be a common characteristic of low power blazars. This is in line with the sequence of blazars relating the observed bolometric luminosity with their overall spectral energy distribution. Detecting new TeV blazars, possibly at different redshifts, is important for studying the particle acceleration process operating in the jet, and it ...
openaire +3 more sources
Galaxies, 2016 This paper discusses the spectral energy distribution (SED) of all blazars with redshift detected by the Fermi satellite and listed in the 3LAC catalog. The so called “blazar sequence” from the phenomenological point of view will be updated, with no theory or modelling. It will be shown that: (i) pure data show that jet and accretion power are related;
openaire +5 more sources