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We treat transformation properties of external radiation fields in the proper frame of a plasma moving with constant speed. The specific spectral energy densities of external isotropic and accretion-disk radiation fields are derived in the…

Astrophysics · Physics 2009-11-07 C. D. Dermer , R. Schlickeiser

Fermi-LAT LCR provide continuous and regularly-sampled gamma-ray light curves, spanning about 14 years, for a large sample of blazars. The log-normal flux distribution and linear RMS-Flux relation of the light curves for a few of Fermi…

High Energy Astrophysical Phenomena · Physics 2023-07-21 Na Wang , Ting-Feng Yi , Liang Wang , Li-Sheng Mao , Zhi-Yuan Pu , Gong-Ming Ning , Wei-Tian Huang , He Lu , Shun Zhang , Yu-Tong Chen , Liang Dong

We are presenting a detailed parameter study of the time-dependent electron injection and kinematics and the self-consistent radiation transport in jets of intermediate and low-frequency peaked BL Lac objects. Using a time-dependent,…

Astrophysics · Physics 2009-11-07 M. Boettcher , J. Chiang

We present the results of a program to monitor the structure of the radio emission in 42 $\gamma$-ray bright blazars (31 quasars and 11 BL Lac objects) with the VLBA at 43, 22, and occasionally 15 and 8.4 GHz, over the period from November…

The spectra of blazars form a sequence which can be parametrized in term of their observed bolometric luminosity. At the most powerful extreme of the sequence we find objects whose jet power can rival the power extracted by accretion, while…

Astrophysics · Physics 2007-05-23 G. Ghisellini

We examine the constraints on the luminosity-dependent density evolution model for the evolution of blazars given the observed spectrum of the diffuse gamma-ray background (DGRB), blazar source-count distribution, and the blazar spectral…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Kevork N. Abazajian , Steve Blanchet , J. Patrick Harding

We investigate the spectral and timing signatures of the internal-shock model for blazars. For this purpose, we develop a semi-analytical model for the time-dependent radiative output from internal shocks arising from colliding relativistic…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 Markus Boettcher , Charles D. Dermer

Very fast variability on scales of minutes is regularly observed in Blazars. The assumption that these flares are emerging from the dominant emission zone of the very high energy (VHE) radiation within the jet challenges current…

High Energy Astrophysical Phenomena · Physics 2016-06-10 Stephan Richter , Felix Spanier

Statistical analyses are invaluable methods used to understand intrinsic emission processes and the unification of extragalactic radio sources. In this paper, we collected radio, X-ray and {\gamma}-ray data of blazars from the Fermi-LAT and…

High Energy Astrophysical Phenomena · Physics 2021-12-08 E. U. Iyida , I. O. Eya , F. C. Odo

The overall spectra (SED) of blazars, from radio to gamma-ray energies, seem to obey well defined trends, with a continuity of properties between blazars of different classes. To quantify this statement we can either investigate their…

Astrophysics · Physics 2007-05-23 Gabriele Ghisellini

With ten years of operation and an exceptional dataset, the Fermi-Large Area Telescope allows us to unveil the detailed composition of the extragalactic $\gamma$-ray sky above $\rm 100\,MeV$. In this paper, we derive the intrinsic…

High Energy Astrophysical Phenomena · Physics 2020-06-09 Lea Marcotulli , Mattia Di Mauro , Marco Ajello

Relativistic jets from accreting supermassive black holes at cosmological distances can be powerful emitters of $\gamma$-rays. However, the precise mechanisms and locations responsible for the dissipation of energy within these jets,…

High Energy Astrophysical Phenomena · Physics 2025-01-03 Sushmita Agarwal , Amit Shukla , Karl Mannheim , Bhargav Vaidya , Biswajit Banerjee

Fermi has provided the largest sample of gamma-ray selected blazars to date. In this work we use a uniformly selected set of 211 BL Lacertae (BL Lac) objects detected by it Fermi during its first year of operation. We have obtained redshift…

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,…

High Energy Astrophysical Phenomena · Physics 2017-05-31 G. Ghisellini , C. Righi , L. Costamante , F. Tavecchio

BL Lac objects are an extreme type of active galactic nuclei (AGNs) that belong to the largest population of $\gamma$-ray sources: blazars. This class of AGNs shows a double-bumped spectral energy distribution that is commonly described in…

High Energy Astrophysical Phenomena · Physics 2020-04-08 E. J. Marchesini , A. Paggi , F. Massaro , N. Masetti , R. D'Abrusco , I. Andruchow , R. de Menezes

A tight correlation between gamma-ray and radio emission is found for a sample of BL Lacertae (BL Lac) objects detected by Fermi Gamma-ray Space Telescope (Fermi) and the Energetic Gamma-Ray Experiment Telescope (EGRET). The gamma-ray…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Fan Li , Xinwu Cao

Context. Blazar flares provide a window into the extreme physical processes occurring in relativistic outflows. Most numerical codes used for modeling blazar emission during flares utilize a simplified continuous-loss description of…

High Energy Astrophysical Phenomena · Physics 2024-07-03 Anton Dmytriiev , Markus Böttcher

Blazars are active galactic nuclei with relativistic jets pointed almost directly at Earth. Blazars are characterized by strong, apparently stochastic flux variability at virtually all observed wavelengths and timescales, from minutes to…

High Energy Astrophysical Phenomena · Physics 2023-02-16 Aryeh Brill

Blazars are thought to emit highly-collimated outflows, so-called jets. By their close alignment to our line of sight, relativistic beaming effects enable us to observe these jets over the whole electromagnetic spectrum up to TeV energies,…

Astrophysics · Physics 2008-08-20 Robert Wagner

In this work, we compiled a sample of 202 Fermi/LAT blazars with available broad line emissions. Out of the 202 sources, 66 have known Doppler factors. The correlation between ($\gamma$-ray) and broad-line emission, and that between radio…

Astrophysics of Galaxies · Physics 2019-03-15 Lixia Zhang , Junhui Fan , Yuhai Yuan
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