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

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We present a study of the effects of ultraviolet (UV) emission from active galactic nuclei (AGN) on the atmospheric composition of planets and potential impact on life. It is expected that all supermassive black holes, which reside at…

Earth and Planetary Astrophysics · Physics 2025-02-11 Kendall I. Sippy , Jake K. Eager-Nash , Ryan C. Hickox , Nathan J. Mayne , McKinley C. Brumback

Active galactic nuclei (AGN) are believed to be promising candidates of extragalactic cosmic-ray accelerators and sources, and associated high-energy neutrino and hadronic gamma-ray emission has been studied for many years. We review models…

High Energy Astrophysical Phenomena · Physics 2019-04-03 Kohta Murase

Active Galactic Nuclei (AGN) are remarkable astronomical sources emitting over the whole electromagnetic spectrum, with different bands providing unique windows on distinct sub-structures and their related physics. AGN come in a large…

High Energy Astrophysical Phenomena · Physics 2023-02-27 Paolo Padovani

This Astro2020 white paper summarizes the unknowns of active galactic nuclei (AGN) physics that could be unveiled thanks to a new, space-born, ultraviolet spectropolarimeter. The unique capabilities of high energy polarimetry would help us…

High Energy Astrophysical Phenomena · Physics 2019-03-14 F. Marin , S. Charlot , B. Agís González , D. Sluse , D. Hutsemékers , A. Labiano , L. Grosset , C. Neiner , J. -C. Bouret

There are several key open questions as to the nature and origin of AGN including: 1) what initiates the active phase, 2) the duration of the active phase, and 3) the effect of the AGN on the host galaxy. Critical new insights to these can…

Instrumentation and Methods for Astrophysics · Physics 2009-04-27 Steve Kraemer , Rogier Windhorst , Kenneth G. Carpenter , Mike Crenshaw , Martin Elvis , Margarita Karovska

Active Galactic Nuclei (AGN) are energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, and present unique observational signatures that cover the full electromagnetic spectrum over more than twenty…

Active Galactic Nuclei (AGN) are highly energetic astrophysical sources powered by accretion onto supermassive black holes in galaxies, which present unique observational signatures covering the full electromagnetic spectrum (and more) over…

High Energy Astrophysical Phenomena · Physics 2023-04-05 Stefano Bianchi , Vincenzo Mainieri , Paolo Padovani

The energy released by Active Galactic Nuclei (AGN) in the form of radiation, winds, or radio plasma jets, is known to impact on the surrounding interstellar medium. The result of these processes, known as AGN (negative) feedback, is…

Astrophysics of Galaxies · Physics 2017-12-15 Raffaella Morganti

We consider the emission of high energy to very high energy $\gamma$-rays in radio-quiet active galactic nuclei (AGN) or the central regions of radio-loud AGN. We use our results to estimate the $\gamma$-ray flux from the central regions of…

Astrophysics · Physics 2011-05-12 P. A. Johnson , A. Mastichiadis , R. J. Protheroe , T. S. Stanev , A. P. Szabo

Active Galactic Nuclei (AGN) are sources of high-energy gamma-rays and are considered to be promising candidates to be sources of high-energy cosmic rays and neutrinos as well. We present and discuss various models for ion acceleration and…

High Energy Astrophysical Phenomena · Physics 2023-11-13 Kohta Murase , Floyd W. Stecker

Growing supermassive black holes (Active Galactic Nuclei; AGN) release energy with the potential to alter their host galaxies and larger-scale environment; a process named "AGN feedback". Feedback is a required component of galaxy formation…

Astrophysics of Galaxies · Physics 2024-04-15 Chris M. Harrison , Cristina Ramos Almeida

Active Galactic Nuclei (AGN) are multiwavelength emitters. To have any hope of understanding them, or even to determine their energy output, we must observe them with many telescopes. I will review what we have learned from broad-band…

Astrophysics · Physics 2007-05-23 Belinda J. Wilkes

(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

Interactions between galaxies are suggested to be a mechanism responsible for feeding Active Galactic Nuclei (AGN). Theoretical models show that interactions are an efficient way to drive gas from the galaxy to the nucleus, however, the…

Astrophysics · Physics 2009-11-10 H. R. Schmitt

Recent astronomical observations reveal that Active Galactic Nuclei (AGN) are sources of high-energy radiation. For example, the Fermi-LAT and Hess telescopes have detected gamma-ray emissions from the cores of several types of AGN's. Even…

High Energy Astrophysical Phenomena · Physics 2013-08-15 J. C. Arteaga-Velazquez , Angelo Martinez

Observing programs comprising multiple scientific objectives will enhance the productivity of NASA's next UV/Visible mission. Studying active galactic nuclei (AGN) is intrinsically important for understanding how black holes accrete matter,…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-17 Gerard Kriss , Nahum Arav , Anton Koekemoer , Smita Mathur , Bradley M. Peterson , Jennifer E. Scott

It is well-known that active galactic nuclei (AGN) are accompanied by winds and outflows, some of which may reach weakly relativistic speeds of about $10$ percent the speed of light. Yet, in spite of their ubiquity, the impact of AGN…

Earth and Planetary Astrophysics · Physics 2022-03-03 A. Ambrifi , A. Balbi , M. Lingam , F. Tombesi , E. Perlman

This volume presents an overview of selected aspects of physical processes occurring in the inner regions of Active Galactic Nuclei (AGN). The observational evidence suggests that strong gravitational fields play a significant role in…

High Energy Astrophysical Phenomena · Physics 2021-11-22 Vladimir Karas , Jiri Svoboda , Michal Zajacek

Active Galactic Nuclei (AGN) are ideal sources for multi-wavelength studies as their emission can cover almost 20 orders of magnitude in frequency from the radio to the gamma-ray band. After reviewing their basic properties, I will assess…

Astrophysics · Physics 2007-05-23 Paolo Padovani

We present a study of the prevalence and luminosity of Active Galactic Nuclei (AGN; traced by optical spectra) as a function of both environment and galaxy interactions. For this study we used a sample of more than 250000 galaxies drawn…

Astrophysics of Galaxies · Physics 2014-11-20 J. Sabater , P. N. Best , T. M. Heckman
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