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Related papers: Active Galactic Nuclei and their Role in Galaxy Ev…

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Effectively finding and identifying active galactic nuclei (AGNs) in dwarf galaxies is an important step in studying black hole formation and evolution. In this work, we examine four mid-IR-selected AGN candidates in dwarf galaxies with…

Astrophysics of Galaxies · Physics 2025-01-20 Megan R. Sturm , Bayli Hayes , Amy E. Reines

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

The variability of active galactic nuclei (AGN) has long held the promise of shedding light on their detailed structure, and possibly other astrophysical phenonema. Different emission mechanisms lead to different patterns of variability in…

Astrophysics · Physics 2009-11-07 M. R. S. Hawkins

Establishing the role of active galactic nuclei (AGN) during the formation of galaxies remains one of the greatest challenges of galaxy formation theory. Towards addressing this, we summarise our recent work investigating: (1) the physical…

Astrophysics of Galaxies · Physics 2021-07-01 C. M. Harrison , S. J. Molyneux , J. Scholtz , M. E. Jarvis

Number of monitoring observations of continuum emission from Active Galactic Nuclei (AGNs) have been made in optical--X-ray bands. The results obtained so far show (i) random up and down on timescales longer than decades, (ii) no typical…

Astrophysics · Physics 2007-05-23 T. Kawaguchi , S. Mineshige

Hard X-ray surveys are an important tool for the study of active galactic nuclei (AGN): they provide almost an unbiased view of absorption in the extragalactic population, allow the study of spectral features such as reflection and high…

High Energy Astrophysical Phenomena · Physics 2013-02-12 Loredana Bassani , M. Molina , A. Malizia , F. Panessa , R. Landi , A. Bazzano , P. Ubertini , A. J. Bird , J. B. Stephen

Today, almost every galaxy spheroid contains a massive black hole: a remnant of, and testament to, a period in its evolution when it contained an active galactic nucleus (AGN). However, the sequence and timescales of the formation of the…

Astrophysics · Physics 2009-11-10 M. J. Page , J. A. Stevens , R. J. Ivison , F. J. Carrera

The Unified Model of Active Galactic Nuclei (UMAGN) is a comprehensive theoretical framework aimed at elucidating the diverse observations of AGN, encompassing quasars and Seyfert galaxies. The Model attributes the observed variations to…

Astrophysics of Galaxies · Physics 2024-09-30 Leonardo de Lima Santos , Samuel Bueno Soltau

Physical processes such as re-ignition, enhancement, and fading of active galactic nuclei (AGN) are not entirely understood because the timeline of these events is expected to last many years. However, it is well known that the differences…

We quantify the presence of Active Galactic nuclei (AGN) in a mass-complete (M_* >5e10 M_sun) sample of 123 star-forming and quiescent galaxies at 1.5 < z < 2.5, using X-ray data from the 4 Ms Chandra Deep Field-South (CDF-S) survey.…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Karen Pardos Olsen , Jesper Rasmussen , Sune Toft , Andrew W. Zirm

Observations at long wavelengths, in the wide interval from a few to 1000 micron, are essential to study diffuse media in galaxies, including all kinds of atomic, ionic and molecular gases and dust grains. Hence they are particularly suited…

Astrophysics · Physics 2007-05-23 Alberto Franceschini

The current generation of flagship X-ray missions, Chandra and XMM-Newton, has changed our understanding of the so-called "cool core" galaxy clusters and groups. Instead of the initial idea that the thermal gas is cooling and flowing toward…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Myriam Gitti , Fabrizio Brighenti , Brian R. McNamara

The issue of a starburst-AGN connection in local and distant galaxies is relevant for understanding galaxy formation and evolution, the star formation and metal enrichment history of the universe, the origin of the extragalactic background…

Astrophysics · Physics 2007-05-23 Sylvain Veilleux

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

Discovering and studying obscured AGN at z>1-3 is important not only to complete the AGN census, but also because they can pinpoint galaxies where nuclear accretion and star-formation are coeval, and mark the onset of AGN feedback. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Fabrizio Fiore

Reionization marks one of the most important phase transitions in the history of the Universe, during which neutral baryonic matter was transformed into ionized plasma. While star-forming galaxies are widely regarded as the primary drivers…

Astrophysics of Galaxies · Physics 2026-01-12 Tong Su , Qi Guo , Wenxiang Pei , Linhua Jiang

Active Galactic Nuclei (AGN) are powered by the accretion of material onto a supermassive black hole (SMBH), and are among the most luminous objects in the Universe. However, the huge radiative power of most AGN cannot be seen directly, as…

Astrophysics of Galaxies · Physics 2018-10-17 Ryan C. Hickox , David M. Alexander

We study the spatially resolved star formation, gas ionisation, and outflow properties of 1813 active galactic nuclei (AGNs) from the MaNGA survey, which we classify into infrared (IR), broad-line (BL), narrow-line (NL), and radio (RD) AGNs…

Astrophysics of Galaxies · Physics 2026-02-18 Gaoxiang Jin , Guinevere Kauffmann , Y. Sophia Dai , Martin J. Hardcastle , Bohan Yue

The last decade saw long-awaited improvements in our understanding of active galactic nuclei (AGN) spectral properties. This contribution reviews some important observational results obtained from optical and UV data as well as constraints…

Astrophysics · Physics 2007-09-19 P. Marziani , J. W. Sulentic , D. Dultzin

We present a measurement of the fraction of cluster galaxies hosting X-ray bright Active Galactic Nuclei (AGN) as a function of clustercentric distance scaled in units of $r_{500}$. Our analysis employs high quality Chandra X-ray and Subaru…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-17 S. Ehlert , A. von der Linden , S. W. Allen , W. N. Brandt , Y. Q. Xue , B. Luo , A. Mantz , R. G. Morris , D. Applegate , P. Kelly