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Related papers: Fossil AGN jets as ultra high energy particle acce…

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Magnetic reconnection is invoked as one of the primary mechanisms to produce energetic particles. We employ large-scale three-dimensional (3D) particle-in-cell simulations of reconnection in magnetically-dominated ($\sigma=10$) pair plasmas…

High Energy Astrophysical Phenomena · Physics 2021-12-15 Hao Zhang , Lorenzo Sironi , Dimitrios Giannios

The majority of the highest energy cosmic rays are thought to be electrically charged: protons or nuclei. Charged particles experience angular deflections as they pass through galactic and extra-galactic magnetic fields. As a consequence…

Astrophysics · Physics 2008-11-26 J. D. Hague , J. A. J. Matthews , B. R. Becker , M. S. Gold

Most of the action in Active Galactic Nuclei (AGN) occurs within a few tens of gravitational radii from the supermassive black hole, where matter in the accretion disk may lose up to almost half of its energy with a copious production of…

We present the results of Hi line observations towards 26 Active Galactic Nuclei (AGN)-hosting and one star-forming dwarf galaxies (Mstar < 10^9.5 Msun) with the 19-beam spectral line receiver of FAST at 1.4 GHz. Our FAST observed targets…

Astrophysics of Galaxies · Physics 2025-12-01 Hong-Ying Chen , Chao-Wei Tsai , Pei Zuo , Niankun Yu , Jialai Wang , Kai Zhang , Guodong Li , Yogesh Chandola , Zheng Zheng , Jingwen Wu , Di Li , Lulu Bao

We argue that the magnetic flux threading the black hole, rather than black hole spin or Eddington ratio, is the dominant factor in launching powerful jets and thus determining the radio loudness of active galactic nuclei (AGN). Most AGN…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Marek Sikora , Mitchell C. Begelman

The observable characteristics of gamma-ray bursts (GRBs) embedded in the accretion disk of active galactic nuclei (AGNs) are mainly determined by the jet propagation within the disk. In the massive collapsar scenario, we consider that the…

High Energy Astrophysical Phenomena · Physics 2025-11-20 Yun-Feng Wei , Tong Liu , Bao-Quan Huang

There is growing consensus that feedback from AGN is the main mechanism responsible for stopping cooling flows in clusters of galaxies. AGN are known to inflate buoyant bubbles that supply mechanical power to the intracluster gas (ICM).…

Astrophysics · Physics 2009-11-13 M. Ruszkowski , T. A. Ensslin , M. Bruggen , S. Heinz , C. Pfrommer

The magnetic field plays a significant role in the phenomenon of highly collimated jets of active galactic nuclei (AGN). Relativistic effects prevent the direct reconstruction of the magnetic field direction as transverse to electric…

High Energy Astrophysical Phenomena · Physics 2023-03-01 Marina S. Butuzova , Alexander B. Pushkarev

Analytical and numerical galaxy-formation models indicate that active galactic nuclei (AGNs) likely play a prominent role in the formation and evolution of galaxies. However, quantifying this effect requires knowledge of how the nuclear…

Astrophysics of Galaxies · Physics 2017-09-07 Raffaella Morganti

Recent results have suggested that active galactic nuclei (AGN) could provide enough photons to reionise the Universe. We assess the viability of this scenario using a semi-numerical framework for modeling reionisation, to which we add a…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-23 Sultan Hassan , Romeel Davé , Sourav Mitra , Kristian Finlator , Benedetta Ciardi , Mario G. Santos

The importance of feedback (radiative and mechanical) from massive black holes at the centers of elliptical galaxies is not in doubt, given the well established relation among black hole mass and galaxy optical luminosity. Here, with the…

Astrophysics of Galaxies · Physics 2015-05-27 L. Ciotti , J. P. Ostriker

We summarize what large surveys of the contemporary universe have taught us about the physics and phenomenology of the processes that link the formation and evolution of galaxies and their central supermassive black holes. We present a…

Astrophysics of Galaxies · Physics 2015-06-19 Timothy Heckman , Philip Best

(Context) Central active galactic nuclei (AGN) are supposed to play a key role in the evolution of their host galaxies. In particular, the dynamical and physical properties of the gas core must be affected by the injected energy. (Aims) Our…

Astrophysics · Physics 2015-06-24 Sebastien Peirani , Scott Kay , Joe Silk

Many Active Galactic Nuclei (AGN) are surrounded by gas which absorbs the radiation produced by accretion onto the central black hole and obscures the nucleus from direct view. The dust component of the gas greatly enhances the effect of…

Astrophysics · Physics 2009-11-13 A. C. Fabian , R. V. Vasudevan , P. Gandhi

Based on a model for the emission of high energy cosmic rays from AGN (Active Galactic Nuclei) that has been proposed by the author, he reviews the status of the GZK cutoff and the correlation of high energy cosmic ray sources with AGN…

Astrophysics · Physics 2008-02-21 Yukio Tomozawa

The disks of Active Galactic Nuclei (AGNs) are expected to be populated by numerous stars, either formed in the outer regions of the disk via gravitational instability, or captured from the nearby nuclear star cluster. Regardless of their…

Astrophysics of Galaxies · Physics 2025-03-07 Gaia Fabj , Alexander J. Dittmann , Matteo Cantiello , Rosalba Perna , Johan Samsing

This paper shows that ultrastrong magnetic fields (such as those of magnetars) and dense astrophysical plasmas can reduce the half life of alpha decaying nuclei by many orders of magnitude. In such environments the conventional…

Nuclear Theory · Physics 2009-11-10 Theodore E. Liolios

The uncertainty surrounding the nature of the heating mechanism for the dust that emits at mid- to far-IR (MFIR) wavelengths in active galaxies limits our understanding of the links between active galactic nuclei (AGN) and galaxy evolution,…

A new mechanism of particle acceleration, based on the resonant interaction of a classical electromagnetic wave (EM) with a quantum wave (associated with a relativistic particle), is explored. In a model illustrative calculation, we study…

High Energy Astrophysical Phenomena · Physics 2022-08-31 S. M. Mahajan , Z. N. Osmanov

Powerful winds driven by active galactic nuclei (AGN) are often invoked to play a fundamental role in the evolution of both supermassive black holes (SMBHs) and their host galaxies, quenching star formation and explaining the tight…

High Energy Astrophysical Phenomena · Physics 2015-03-26 F. Tombesi , M. Melendez , S. Veilleux , J. N. Reeves , E. Gonzalez-Alfonso , C. S. Reynolds