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Related papers: Origin of Blazar Activity

200 papers

Most of the light from blazars, active galactic nuclei with jets of magnetized plasma that point nearly along the line of sight, is produced by high-energy particles, up to $\sim 1$ TeV. Although the jets are known to be ultimately powered…

High Energy Astrophysical Phenomena · Physics 2023-09-06 Ioannis Liodakis , Alan P. Marscher , Iván Agudo , Andrei V. Berdyugin , Maria I. Bernardos , Giacomo Bonnoli , George A. Borman , Carolina Casadio , Víctor Casanova , Elisabetta Cavazzuti , Nicole Rodriguez Cavero , Laura Di Gesu , Niccoló Di Lalla , Immacolata Donnarumma , Steven R. Ehlert , Manel Errando , Juan Escudero , Maya García-Comas , Beatriz Agís-González , César Husillos , Jenni Jormanainen , Svetlana G. Jorstad , Masato Kagitani , Evgenia N. Kopatskaya , Vadim Kravtsov , Henric Krawczynski , Elina Lindfors , Elena G. Larionova , Grzegorz M. Madejski , Frédéric Marin , Alessandro Marchini , Herman L. Marshall , Daria A. Morozova , Francesco Massaro , Joseph R. Masiero , Dimitri Mawet , Riccardo Middei , Maxwell A. Millar-Blanchaer , Ioannis Myserlis , Michela Negro , Kari Nilsson , Stephen L. O'Dell , Nicola Omodei , Luigi Pacciani , Alessandro Paggi , Georgia V. Panopoulou , Abel L. Peirson , Matteo Perri , Pierre-Olivier Petrucci , Juri Poutanen , Simonetta Puccetti , Roger W. Romani , Takeshi Sakanoi , Sergey S. Savchenko , Alfredo Sota , Fabrizio Tavecchio , Samaporn Tinyanont , Andrey A. Vasilyev , Zachary R. Weaver , Alexey V. Zhovtan , Lucio A. Antonelli , Matteo Bachetti , Luca Baldini , Wayne H. Baumgartner , Ronaldo Bellazzini , Stefano Bianchi , Stephen D. Bongiorno , Raffaella Bonino , Alessandro Brez , Niccoló Bucciantini , Fiamma Capitanio , Simone Castellano , Stefano Ciprini , Enrico Costa , Alessandra De Rosa , Ettore Del Monte , Alessandro Di Marco , Victor Doroshenko , Michal Dovčiak , Teruaki Enoto , Yuri Evangelista , Sergio Fabiani , Riccardo Ferrazzoli , Javier A. Garcia , Shuichi Gunji , Kiyoshi Hayashida , Jeremy Heyl , Wataru Iwakiri , Vladimir Karas , Takao Kitaguchi , Jeffery J. Kolodziejczak , Fabio La Monaca , Luca Latronico , Simone Maldera , Alberto Manfreda , Andrea Marinucci , Giorgio Matt , Ikuyuki Mitsuishi , Tsunefumi Mizuno , Fabio Muleri , Stephen C. -Y. Ng , Chiara Oppedisano , Alessandro Papitto , George G. Pavlov , Melissa Pesce-Rollins , Maura Pilia , Andrea Possenti , Brian D. Ramsey , John Rankin , Ajay Ratheesh , Carmelo Sgró , Patrick Slane , Paolo Soffitta , Gloria Spandre , Toru Tamagawa , Roberto Taverna , Yuzuru Tawara , Allyn F. Tennant , Nicolas E. Thomas , Francesco Tombesi , Alessio Trois , Sergey Tsygankov , Roberto Turolla , Jacco Vink , Martin C. Weisskopf , Kinwah Wu , Fei Xie , Silvia Zane

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. The modelling of their spectral energy…

High Energy Astrophysical Phenomena · Physics 2022-11-08 Hélène Sol , Andreas Zech

Blazar jets are renowned for their rapid violent variability and multiwavelength flares, however, the physical processes responsible for these flares are not well understood. In this paper we develop a time-dependent inhomogeneous fluid jet…

High Energy Astrophysical Phenomena · Physics 2017-12-06 William J. Potter

The high energy peaked blazars are known to undergo episodes of flaring in GeV-TeV gamma-rays involving different time scales and the flaring mechanism is not well understood despite long term simultaneous multiwavelength observations.…

High Energy Astrophysical Phenomena · Physics 2019-10-16 Sarira Sahu , Carlos E. Lopez Fortin , Shigehiro Nagataki

One of remarkable features of the gamma ray blazar Markarian 501 is the reported shape of the TeV spectrum, which during strong flares of the source remains essentially stable despite dramatic variations of the absolute gamma-ray flux. I…

Astrophysics · Physics 2010-04-06 F. A. Aharonian

The blazar 3C 279 is well known for its rapid and large-amplitude variability. On 20 December 2013, the source exhibited an orphan {\gamma}-ray flare characterized by a flux-doubling timescale of a few hours, a very hard spectrum, a…

High Energy Astrophysical Phenomena · Physics 2026-05-04 Sébastien Le Bihan , Anton Dmytriiev , Andreas Zech

BeppoSAX is best known for its role in the disclosure of the Gamma-Ray Burst mystery, but it has also improved our understanding of jetted sources in general, and blazars in particular. On the interpretational side, we are curious to see if…

Astrophysics · Physics 2007-05-23 G. Ghisellini , A. Celotti

Blazars are strongly variable sources that occasionally show spectacular flares visible in various energy bands. These flares are often, but not always, correlated. In a number of cases the peaks of optical flares are found to be somewhat…

High Energy Astrophysical Phenomena · Physics 2015-06-11 Mateusz Janiak , Marek Sikora , Krzysztof Nalewajko , Rafał Moderski , Greg M. Madejski

Very-high-energy gamma-ray flares of TeV blazars are generally accompanied by simultaneous flaring activity in X-rays. The recent observations by the Whipple collaboration of an ``orphan'' TeV flare of 1ES 1959+650 (without simultaneous…

Astrophysics · Physics 2009-11-10 M. Boettcher

With their jet pointing towards us, blazars are ideal tools to study the physics and structure of extragalactic jets. Their powerful jets are cosmic particle accelerators and are alleged to be one of the production sites of the high-energy…

High Energy Astrophysical Phenomena · Physics 2025-11-25 Claudia M. Raiteri

The emission spectra of TeV blazars extend up to tens of TeV and the emission mechanism of the TeV $\gamma$-rays is explained by synchrotron self-Compton scattering in leptonic models. In these models the time variabilities of X-rays and…

Astrophysics · Physics 2008-11-26 Masaaki Kusunose , Fumio Takahara

Blazars are well known for the violent variability from the radio to gamma-ray wavelengths. In this paper, we present a brief summary of the X-ray variability recently obtained for TeV blazars. We also point out the probable similarities of…

Astrophysics · Physics 2007-05-23 Y. H. Zhang

Context: An electron-positron beam escaping from the magnetospheric vacuum gap of an accreting black hole interacts with recombination-line photons from surrounding gas clouds. Inverse-Compton scattering and subsequent pair production…

High Energy Astrophysical Phenomena · Physics 2021-02-17 Christoph Wendel , Josefa Becerra González , David Paneque , Karl Mannheim

The non-thermal spectra of blazars, observed from radio to GeV/TeV gamma-rays, reveal two pronounced components, both produced by radiation by energetic particles. One peaks in the IR - to soft X-ray band, radiating via the synchrotron…

Astrophysics · Physics 2009-10-31 Tadayuki Takahashi , Greg Madejski , Hidetoshi Kubo

Blazars are promising sources of extragalactic high-energy astrophysical neutrinos, detected at energies $\gtrsim 10$ TeV by the IceCube neutrino observatory. Here, we report the first-ever broadband timing and spectral study of the…

High Energy Astrophysical Phenomena · Physics 2026-05-05 Suvas Chandra Chaudhary , Saikat Das , Raj Prince , Brian van Soelen

We are leading a comprehensive multi-waveband monitoring program of 34 gamma-ray bright blazars designed to locate the emission regions of blazars from radio to gamma-ray frequencies. The "maps" are anchored by sequences of images in both…

High Energy Astrophysical Phenomena · Physics 2015-05-20 Alan Marscher , Svetlana G. Jorstad , Valeri M. Larionov , Margo F. Aller , Anne Lahteenmaki

In this paper we extend our approach to modeling multifrequency emission variability from blazars to include external-radiation Compton (ERC) emission and electron energy losses from inverse Compton scattering of seed photons originating…

Astrophysics · Physics 2009-11-11 Andrei Sokolov , Alan P. Marscher

The power carried by the jet of blazars is large, compared to the luminosity produced by their accretion disk, and is probably in the form of kinetic energy of a normal electron-proton plasma. The Poynting flux is modest, as suggested by…

Astrophysics · Physics 2008-07-18 G. Ghisellini

Blazars are a subclass of AGN and flaring in multi-TeV gamma-ray seems to be the major activity in high energy blazars a subgrup of blazars. Flaring is also unpredictable and switches between quiescent and active states involving different…

High Energy Astrophysical Phenomena · Physics 2019-07-03 Sarira Sahu

A subset of blazars emit TeV gamma rays which annihilate and pair produce on the extragalactic background light. We have argued in Broderick et al. (2011, Paper I) that plasma beam instabilities can dissipate the pairs' energy locally. This…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Christoph Pfrommer , Philip Chang , Avery E. Broderick