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Related papers: Why does Low-Luminosity AGN Fueling Remain an Unso…

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From a Chandra sample of active galactic nuclei (AGNs) in nearby galaxies, we find that for low-luminosity AGNs (LLAGNs), either the intrinsic absorption column density, or the fraction of absorbed AGNs, positively scales with the Eddington…

High Energy Astrophysical Phenomena · Physics 2018-06-27 Rui She , Luis C. Ho , Hua Feng , Can Cui

The photoionization model of narrow-line regions (NLRs) in active galactic nuclei (AGNs) has been investigated for decades. Many published models are restricted to simple linear scaling abundance relations, dust-free assumption, uniform AGN…

Astrophysics of Galaxies · Physics 2023-05-23 Peixin Zhu , Lisa J. Kewley , Ralph S. Sutherland

Using a simple description of feedback from black hole (BH) growth, we develop an analytic model for the fueling of Seyferts (low-luminosity AGN) and their relation to their host galaxies, Eddington ratio distributions, and cosmological…

Astrophysics · Physics 2009-11-11 Philip F. Hopkins , Lars Hernquist

Surveys of Active Galactic Nuclei (AGN) in different observational regimes seem to give different answers for the behaviour of the obscured fraction with luminosity. Based on the complex spectra seen in recent studies, we note that partial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Jack H. Mayo , Andy Lawrence

Unified schemes of active galactic nuclei (AGN) require an obscuring dusty torus around the central engine. The compact sizes (only a few pc) determined in recent high-resolution observations require that the obscuring matter be clumpy and…

Astrophysics · Physics 2011-02-11 Moshe Elitzur , Isaac Shlosman

Active galactic nuclei (AGN) in the early Universe are thought to be prominent sources of energy and ionizing photons that affected the growth of their host galaxy and their environment. However, it is still unclear how the supermassive…

Astrophysics of Galaxies · Physics 2023-06-28 Junehyoung Jeon , Boyuan Liu , Volker Bromm , Steven L. Finkelstein

The origin of obscuration in Active Galactic Nuclei (AGN) is still a matter of contention. It is unclear whether obscured AGN are primarily due to line-of-sight effects, a transitory, dust-enshrouded phase in galaxy evolution, or a…

I discuss some recent observational results in the research of nearby active galactic nuclei (AGN). These results cover three main topics: (i) evidences for the current paradigm for AGN's, which include a nuclear supermassive blackhole…

Astrophysics · Physics 2007-05-23 Thaisa Storchi-Bergmann

Supermassive Black Holes grow at the center of galaxies in consonance with them. In this review we discuss the mass feeding mechanisms that lead to this growth in Active Galactic Nuclei (AGN), focusing on constraints derived from…

Astrophysics of Galaxies · Physics 2019-04-09 Thaisa Storchi-Bergmann , Allan Schnorr-Müller

A majority of the active galactic nuclei (AGN) in the local Universe are classified as low-luminosity AGN (LLAGN), having bolometric luminosities $\lesssim 10^{42} \ \mathrm{erg \ s^{-1}}$. Although high-energy gamma-ray emission is…

High Energy Astrophysical Phenomena · Physics 2026-04-08 Chris Karwin , Nikita Khatiya , Margot Boughelilba , Xiurui Zhao , Anita Reimer , Marco Ajello

To understand the physical origin of the close connection between supermassive black holes and their host galaxies, it is vital to investigate star formation properties in active galaxies. Using a large dataset of nearby type 1 active…

Astrophysics of Galaxies · Physics 2019-05-08 Minjin Kim , Luis C. Ho

We present an X-ray analysis of fourteen nearby (z < 0.044) AGN in low mass galaxies (M_* <= 5*10^9 Msun) selected based on their optical variability (Baldassare et al. 2020). Comparing and contrasting different AGN selection techniques in…

Astrophysics of Galaxies · Physics 2023-08-09 Alexander Messick , Vivienne Baldassare , Marla Geha , Jenny Greene

Our goal is to find a minimalistic model that describes the luminosity function and large-scale clustering bias of the X-ray-selected AGN in the general framework of the concordance LCDM model. We assume that a simple population-averaged…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Gert Hütsi , Marat Gilfanov , Rashid Sunyaev

Recent observations show that the space density of luminous active galactic nuclei (AGNs) peaks at higher redshifts than that of faint AGNs. This downsizing trend in the AGN evolution seems to be contradictory to the hierarchical structure…

Astrophysics of Galaxies · Physics 2014-10-02 Motohiro Enoki , Tomoaki Ishiyama , Masakazu A. R. Kobayashi , Masahiro Nagashima

Among the most extreme objects in the Universe, active galactic nuclei (AGN) are luminous centers of galaxies where a black hole feeds on surrounding matter. The variability patterns of the light emitted by an AGN contain information about…

Instrumentation and Methods for Astrophysics · Physics 2021-06-22 Ji Won Park , Ashley Villar , Yin Li , Yan-Fei Jiang , Shirley Ho , Joshua Yao-Yu Lin , Philip J. Marshall , Aaron Roodman

Black holes release energy via the production of photons in their accretion discs but also via the acceleration of jets. We investigate the relative importance of these two paths over cosmic time by determining the mechanical luminosity…

Astrophysics · Physics 2009-11-13 A. Cattaneo , P. N. Best

Low luminosity active galactic nuclei (LLAGN) probe accretion physics in the low Eddington regime and can provide additional clues about galaxy evolution. AGN variability is ubiquitous and thus provides a reliable tool for finding AGN. We…

Many X-ray bright active galactic nuclei (AGN) are predicted to follow an extended stage of obscured black hole growth. In support of this picture we examine the X-ray undetected AGNs in the COSMOS field and compare their host galaxies with…

We investigate the effect of active galactic nucleus (AGN) variability on the observed connection between star formation and black hole accretion in extragalactic surveys. Recent studies have reported relatively weak correlations between…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Ryan C. Hickox , James R. Mullaney , David M. Alexander , Chien-Ting J. Chen , Francesca M. Civano , Andy D. Goulding , Kevin N. Hainline

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
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