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Related papers: Gamma-rays in the radio galaxy 3C 84: A complex si…

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We review the high energy properties of Misaligned AGNs associated with gamma-ray sources detected by Fermi in 24 months of survey. Most of them are nearby emission low power radio galaxies (i.e FRIs) which probably have structured jets. On…

High Energy Astrophysical Phenomena · Physics 2019-08-14 Paola Grandi

Before the launch of the Fermi satellite only two classes of Active Galactic Nuclei (AGN) were known to generate relativistic jets and thus to emit up to the gamma-ray energy range: blazars and radio galaxies, both hosted in giant…

High Energy Astrophysical Phenomena · Physics 2019-08-13 F. D'Ammando , M. Orienti , J. Finke , M. Giroletti , J. Larsson

The exact location of the $\gamma$-ray emitting region in blazar jets has long been a matter of debate. However, the location has important implications about the emission processes, geometric and physical parameters of the jet, as well as…

High Energy Astrophysical Phenomena · Physics 2025-05-21 Maitreya Kundu , Arit Bala , Saugata Barat , Ritaban Chatterjee

The $\gamma$-ray production mechanism and its localization in blazars are still a matter of debate. The main goal of this paper is to constrain the location of the high-energy emission in the blazar TXS 2013+370 and to study the physical…

Astrophysics of Galaxies · Physics 2020-02-19 E. Traianou , T. P. Krichbaum , B. Boccardi , R. Angioni , B. Rani , J. Liu , E. Ros , U. Bach , K. V. Sokolovsky , S. Kiehlmann , M. Gurwell , J. A. Zensus

Active Galactic Nuclei (AGN) sources feature supermassive black holes that launch relativistic plasma jets. They are key $\gamma$-ray sources providing a unique laboratory for studying extreme particle acceleration and plasma physics.…

High Energy Astrophysical Phenomena · Physics 2026-02-03 Luana Passos-Reis , Elisabete M. de Gouveia Dal Pino , Tarek Hassan , Santiago Pita , Alberto Domínguez

The nearest active radio galaxy Centaurus (Cen) A is a gamma-ray emitter in GeV to TeV energy scale. The High Energy Stereoscopic System (H.E.S.S.) and non-simultaneous Fermi-LAT observation indicate an unusual spectral hardening above few…

High Energy Astrophysical Phenomena · Physics 2021-02-02 Prabir Banik , Arunava Bhadra , Abhijit Bhattacharyya

Beams of ultra-relativistic electrons in blazar jets develop pair cascades interacting with ambient soft photons. Employing coupled kinetic equations with escape terms, we model the unsaturated pair cascade spectrum. We assume that the…

High Energy Astrophysical Phenomena · Physics 2021-08-06 Christoph Wendel , Josefa Becerra González , Amit Shukla , David Paneque , Karl Mannheim

Analysis is presented on 15 months of data taken with the Large Area Telescope (LAT) on the Fermi Gamma-ray Space Telescope for 11 non-blazar AGNs, including 7 FRI radio galaxies and 4 FRII radio sources consisting of 2 FRII radio galaxies…

High Energy Astrophysical Phenomena · Physics 2017-02-22 LAT Collaboration

In March 2018, Mukherjee (2018) reported the detection by VERITAS of very-high-energy emission (VHE; > 100 GeV) from 3C 264. This is the sixth, and second most distant, radio galaxy ever detected in the TeV regime. In this article we…

High Energy Astrophysical Phenomena · Physics 2019-07-10 B. Boccardi , G. Migliori , P. Grandi , E. Torresi , F. Mertens , V. Karamanavis , R. Angioni , C. Vignali

The Fermi Gamma-ray Space Telescope has detected the gamma-ray glow emanating from the giant radio lobes of the radio galaxy Centaurus A. The resolved gamma-ray image shows the lobes clearly separated from the central active source. In…

High Energy Astrophysical Phenomena · Physics 2010-06-22 LAT Collaboration

We present a multi-wavelength study of IC 1531 (z=0.02564), an extragalactic radio source associated with the $\gamma$-ray object 3FGL J0009.9-3206 and classified as a blazar of uncertain type in the Third Fermi Large Area Telescope AGN…

High Energy Astrophysical Phenomena · Physics 2018-10-17 T. Bassi , G. Migliori , P. Grandi , C. Vignali , M. A. Pérez-Torres , R. D. Baldi , E. Torresi , A. Siemiginowska , C. Stanghellini

Jets associated with Active Galactic Nuclei (AGN) have been observed for almost a century, initially at optical and radio wavelengths. They are now widely accepted as "exhausts" produced electromagnetically by the central, spinning, massive…

High Energy Astrophysical Phenomena · Physics 2015-11-25 R. Blandford , W. East , K. Nalewajko , Y. Yuan , J. Zrake

We present a summary of the observation strategy of TANAMI (Tracking Active Galactic Nuclei with Austral Milliarcsecond Interferometry), a monitoring program to study the parsec-scale structure and dynamics of relativistic jets in active…

It is well-known that the $\gamma$-ray emission in blazars originate in the relativistic jet pointed at the observers. However, it is not clear whether the exact location of the GeV emission is less than a pc from the central engine, such…

High Energy Astrophysical Phenomena · Physics 2022-07-20 Saugata Barat , Ritaban Chatterjee , Kaustav Mitra

Fast radio bursts (FRBs) are one of the most exciting new mysteries of astrophysics. Their origin is still unknown, but recent observations seems to link them to Soft Gamma Repeaters and, in particular, to magnetar giant flares (MGFs). The…

High Energy Astrophysical Phenomena · Physics 2021-09-23 Giacomo Principe , Nicola Omodei , Niccolò Di Lalla , Leonardo Di Venere , Francesco Longo

IC 310 has recently been identified as a gamma-ray emitter based on observations at GeV energies with Fermi-LAT and at very high energies (VHE, E > 100 GeV) with the MAGIC telescopes. Despite IC 310 having been classified as a radio galaxy…

High Energy Astrophysical Phenomena · Physics 2019-08-15 J. Sitarek , D. Eisenacher Glawion , K. Mannheim , P. Colin , M. Kadler , R. Schultz , F. Krauß , E. Ros , U. Bach , J. Wilms

We are compiling a new list of gamma-ray jetted active galactic nuclei (AGN), starting from the fourth catalog of point sources of the Fermi Large Area Telescope (LAT). Our aim is to prepare a list of jetted AGN with known redshifts and…

High Energy Astrophysical Phenomena · Physics 2021-10-06 L. Foschini , M. L. Lister , S. Antón , M. Berton , S. Ciroi , M. J. M. Marchã , M. Tornikoski , E. Järvelä , P. Romano , S. Vercellone , E. Dalla Bontà

Flaring activity from the jets of active galactic nuclei has been studied for several decades, closely related to the loading and evolution of the jet. In this work, we focus on the sub-hundred parsec jet region, well traced by non-thermal…

High Energy Astrophysical Phenomena · Physics 2026-04-07 Alina Kochocki , Emma Kun , Sam Hori

3C84 (NGC1275) is one of the brightest radio sources in the mm radio-bands, which led to a plethora of VLBI observations at numerous frequencies over the years. They reveal a two-sided jet structure, with an expanding but not…