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Related papers: The evolution of obscured accretion

200 papers

The properties of Compton-thick AGN are reviewed, with particular emphasis on BeppoSAX hard X-ray observations. I also discuss evidence for the presence of Compton-thick, circumnuclear matter in unobscured AGN, and I briefly introduce the…

Astrophysics · Physics 2007-05-23 Giorgio Matt

AGN are known to have complex X-ray spectra that depend on both the properties of the accreting SMBH (e.g. mass, accretion rate) and the distribution of obscuring material in its vicinity ("torus"). Often however, simple and even unphysical…

High Energy Astrophysical Phenomena · Physics 2014-05-08 J. Buchner , A. Georgakakis , K. Nandra , L. Hsu , C. Rangel , M. Brightman , A. Merloni , M. Salvato , J. Donley , D. Kocevski

We investigate how hierarchical models for the co-evolution of the massive black hole (MBH) and AGN population can reproduce the observed faint X-ray counts. We find that the main variable influencing the theoretical predictions is the…

Astrophysics · Physics 2009-11-11 Marta Volonteri , Ruben Salvaterra , Francesco Haardt

We perform X-ray spectral analyses to derive characteristics (e.g., column density, X-ray luminosity) of $\approx$10,200 active galactic nuclei (AGNs) in the XMM-Spitzer Extragalactic Representative Volume Survey (XMM-SERVS), which was…

A recent revision of black hole scaling relations (Kormendy & Ho 2013), indicates that the local mass density in black holes should be increased by up to a factor of five with respect to previously determined values. The local black hole…

Astrophysics of Galaxies · Physics 2015-02-11 A. Comastri , R. Gilli , A. Marconi , G. Risaliti , M. Salvati

We search for high-redshift (z>4.5) X-ray AGNs in the deep central (off-axis angle <5.7') region of the 7 Ms Chandra Deep Field-South X-ray image. We compile an initial candidate sample from direct X-ray detections. We then probe more…

Astrophysics of Galaxies · Physics 2020-03-11 L. L. Cowie , A. J. Barger , F. E. Bauer , J. Gonzalez-Lopez

We discuss the abundance of Compton-thick AGN as estimated by the most recent population synthesis models of the cosmic X-ray background. Only a small fraction of these elusive objects have been detected so far, in line with the model…

Astrophysics · Physics 2009-11-13 R. Gilli , A. Comastri , C. Vignali , G. Hasinger

The XLF of AGN offers a robust tool to study the evolution and the growth of SMBHs over cosmic time. Owing to the limited area probed by X-ray surveys, optical surveys are routinely used to probe the accretion in the high redshift Universe…

(abridged) We take advantage of the deep Chandra and Spitzer coverage of a large area (more than 10 times the area covered by the Chandra deep fields, CDFs in the COSMOS field, to extend the search of highly obscured, Compton-thick active…

The co-evolution of host galaxies and the active black holes which reside in their centre is one of the most important topics in modern observational cosmology. Here we present a study of the properties of obscured Active Galactic Nuclei…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 M. Brusa , F. Fiore , P. Santini , A. Grazian , A. Comastri , G. Zamorani , G. Hasinger , A. Merloni , F. Civano , A. Fontana , V. Mainieri

For over 60 years, the scientific community has studied actively growing central super-massive black holes (active galactic nuclei -- AGN) but fundamental questions on their genesis remain unanswered. Numerical simulations and theoretical…

Deep field observations are an essential tool to probe the cosmological evolution of galaxies. In this context, X-ray deep fields provide information about some of the most energetic cosmological objects: active galactic nuclei (AGN).…

Astrophysics · Physics 2007-05-23 G. Hasinger , A. Mueller

We use a coupled model of the formation and evolution of galaxies and black holes (BH) to study the evolution of active galactic nuclei (AGN) in a cold dark matter universe. The model predicts the BH mass, spin and mass accretion history.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 N. Fanidakis , C. M. Baugh , A. J. Benson , R. G. Bower , S. Cole , C. Done , C. S. Frenk , R. C. Hickox , C. Lacey , C. del P. Lagos

Understanding the AGN-galaxy co-evolution, feedback processes, and the evolution of Black Hole Accretion rate Density (BHAD) requires accurately estimating the contribution of obscured Active Galactic Nuclei (AGN). However, detecting these…

Deep X-ray surveys have shown that the cosmic X-ray background (XRB) is largely due to the accretion onto supermassive black holes, integrated over the cosmic time. These surveys have resolved more than 80% of the 0.1-10 keV X-ray…

Astrophysics · Physics 2011-06-30 Guenther Hasinger , the CDF-S team

Population synthesis models of actively accreting super-massive black holes (or active galactic nuclei -- AGN) predict a large fraction that must grow behind dense, obscuring screens of gas and dust. Deep X-ray surveys are thought to have…

Astrophysics of Galaxies · Physics 2020-07-22 Erini Lambrides , Marco Chiaberge , Timothy Heckman , Roberto Gilli , Fabio Vito , Colin Norman

The cosmic black hole accretion density (BHAD) is critical for our understanding of the formation and evolution of supermassive black holes (BHs). However, at high redshifts ($z>3$), X-ray observations report BHADs significantly ($\sim 10$…

Astrophysics of Galaxies · Physics 2021-11-24 Guang Yang , Vicente Estrada-Carpenter , Casey Papovich , Fabio Vito , Jonelle L. Walsh , Zhiyuan Yao , Feng Yuan

The estimate of the number and space density of obscured AGN over cosmic time still represents an open issue. While the obscured AGN population is a key ingredient of the X-ray background synthesis models and is needed to reproduce its…

Astrophysics of Galaxies · Physics 2019-05-29 M. -M. La Caria , C. Vignali , G. Lanzuisi , C. Gruppioni , F. Pozzi

We investigate the Eddington ratio distribution of X-ray selected broad-line active galactic nuclei (AGN) in the redshift range 1.0<z<2.2, where the number density of AGNs peaks. Combining the optical and Subaru/FMOS near-infrared…

Astrophysics of Galaxies · Physics 2016-01-20 Hyewon Suh , Guenther Hasinger , Charles Steinhardt , John D. Silverman , Malte Schramm

We combine bright XMM data with the Chandra Deep Field South observations in order to explore the behavior of the intrinsic AGN absorption, as a function of redshift and luminosity.Our sample consists of 359 sources selected in the hard 2-8…

Astrophysics · Physics 2009-11-11 A. Akylas , I. Georgantopoulos , A. Georgakakis , S. Kitsionas , E. Hatziminaoglou