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Related papers: Active Galactic Nuclei: Boon or Bane for Biota?

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Active Galactic Nuclei (AGN) are believed to be powered by accretion of matter onto a supermassive black hole. A fundamental ingredient in shaping our understanding of AGN is their variability across the entire electromagnetic spectrum.…

High Energy Astrophysical Phenomena · Physics 2025-09-08 Maurizio Paolillo , Iossif Papadakis

In a series of papers based on the FIRST and Sloan Digital Sky Surveys (SDSS), we investigate the local population of star-forming galaxies and Active Galactic Nuclei (AGN) in order to clarify the link between these two types of activity,…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-25 Pietro M. Reviglio , David J. Helfand

High-energy astrophysical events, particularly Gamma Ray Bursts (GRBs), have been proposed as significant contributors to mass extinction events on Earth-like planets in most of the galaxy, internal to our radius in it. This paper examines…

Earth and Planetary Astrophysics · Physics 2026-03-20 Matan Sade , Aviv Tsarfati , Ofek Birnholtz

The underlying hypothesis of this work is that the active galactic nuclei (AGNs) are wormhole mouths rather than supermassive black holes (SMBHs). Under some - quite general - assumptions such wormholes may emit gamma radiation as a result…

High Energy Astrophysical Phenomena · Physics 2020-09-02 M. Yu. Piotrovich , S. V. Krasnikov , S. D. Buliga , T. M. Natsvlishvili

Active Galactic Nuclei (AGN) can be probed by at different regions of the electromagnetic spectrum: e.g., radio observations reveal the nature of their relativistic jets and their magnetic fields, and complementarily, X-ray observations…

Active Galactic Nuclei (AGNs) and their relativistic jets belong to the most promising class of ultra-high-energy cosmic ray (UHECR) accelerators. This compact review summarises basic experimental findings by recent instruments, and…

High Energy Astrophysical Phenomena · Physics 2022-11-23 Frank M. Rieger

Galactic outflows, driven by active galactic nuclei (AGN), play a crucial role in galaxy formation and in the self-regulated growth of supermassive black holes (BHs). AGN feedback couples to and affects gas, rather than stars, and in many,…

Astrophysics of Galaxies · Physics 2018-04-10 Tilman Hartwig , Marta Volonteri , Gohar Dashyan

Supermassive black holes (SMBHs) have been found to be ubiquitous in the nuclei of early-type galaxies and of bulges of spirals. There are evidences of a tight correlation between the SMBH masses, the velocity dispersions of stars in the…

Astrophysics of Galaxies · Physics 2018-02-23 Gianfranco De Zotti

Active galactic nuclei (AGN) provide energetic feedback necessary to `turn off' star formation in high-mass galaxies (M$_{\rm halo} \geq $ 10$^{12.5}$ M$_{\odot}$, $10.4 \leq \log(\frac{M_*}{M_\odot}) \leq 11$) as observed. Cosmic rays…

Astrophysics of Galaxies · Physics 2026-04-14 Charvi Goyal , Sam B. Ponnada , Philip F. Hopkins , Sarah Wellons , Jose A. Benavides , Kung-Yi Su

Active Galactic Nuclei (AGN) are known to show flux variability over all observable timescales and across the entire electromagnetic spectrum. Over the past decade, a growing number of sources have been observed to show dramatic flux and…

Astrophysics of Galaxies · Physics 2022-11-11 Claudio Ricci , Benny Trakhtenbrot

The role of active galactic nuclei (AGN) feedback in dwarf galaxies remains poorly understood, with conventional wisdom suggesting it primarily suppresses star formation. Using high-resolution MACER3D simulations that directly resolve the…

Astrophysics of Galaxies · Physics 2025-10-27 Tingfang Su , Suoqing Ji , Feng Yuan , Haojie Xia , Yuxuan Zou

Active Galactic Nuclei (AGN) represent the growth phases of the supermassive black holes in the center of almost every galaxy. Powerful, highly ionized winds, with velocities $\sim 0.1- 0.2c$ are a common feature in X--ray spectra of…

Astrophysics of Galaxies · Physics 2015-09-23 Andrew King , Ken Pounds

In Active Galactic Nuclei (AGNs) the presence of a star cluster around the central black hole can have several effects on the dynamics and the emission of the global system. In this paper we analyze the interaction of stellar atmospheres…

Astrophysics · Physics 2009-11-07 Guidetta Torricelli-Ciamponi , Paola Pietrini

We investigate the astrophysics of radio-emitting star-forming galaxies and ac- tive galactic nuclei (AGNs), and elucidate their statistical properties in the radio band including luminosity functions, redshift distributions, and number…

Astrophysics of Galaxies · Physics 2017-06-28 Claudia. Mancuso , A. Lapi , I. Prandoni , I. Obi , J. Gonzalez-Nuevo , F. Perrotta , A. Bressan , A. Celotti , L. Danese

Cosmological simulations fail to reproduce realistic galaxy populations without energy injection from active galactic nuclei (AGN) into the interstellar medium (ISM) and circumgalactic medium (CGM); a process called `AGN feedback'.…

Astrophysics of Galaxies · Physics 2024-11-20 C. M. Harrison , A. Girdhar , S. R. Ward

During the peak of their accretion phase, supermassive black holes in galactic cores are known to emit very high levels of ionizing radiation, becoming visible over intergalactic distances as quasars or active galactic nuclei (AGN). Here,…

Earth and Planetary Astrophysics · Physics 2017-12-01 Amedeo Balbi , Francesco Tombesi

It is commonly accepted that active galactic nuclei (AGN) have a strong impact upon the evolution of their host galaxies, but the processes by which they do so are not fully understood. We aim to further the understanding of AGN feeding and…

Astrophysics of Galaxies · Physics 2025-01-22 Sophie L. Robbins , Sandra I. Raimundo , Matthew A. Malkan

Presently there are several classes of detected gamma-ray extragalatic sources. They are mostly associated to active galactic nuclei (AGN) and (at soft gamma rays) to gamma-ray bursts (GRB), but not only. Active galactic nuclei consist of…

High Energy Astrophysical Phenomena · Physics 2011-09-09 V. Bosch-Ramon

In the framework of a systematic ALMA study of IR-selected main-sequence and starburst galaxies at z~1-1.7 at typical ~1" resolution, we report on the effects of mid-IR- and X-ray-detected active galactic nuclei (AGN) on the reservoirs and…

Supermassive black holes (BH) are powerful sources of energy that are already in place at very early epochs of the Universe (by z=6). Using hydrodynamical simulations of the formation of a massive M_vir=5 10^11 M_sun halo by z=6 (the most…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Yohan Dubois , Christophe Pichon , Julien Devriendt , Joseph Silk , Martin Haehnelt , Taysun Kimm , Adrianne Slyz