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The evolution of the luminosity function (LF) of Active Galactic Nuclei (AGNs) at $z \gtrsim 5$ represents a key constraint to understand their contribution to the ionizing photon budget necessary to trigger the last phase transition in the…

A supermassive black hole has been found at the centre of nearly every galaxy observed with sufficient sensitivity. The masses of these black holes are observed to increase with either the total mass or the mean (random) velocity of the…

We argue that the magnetic flux threading the black hole, rather than black hole spin or Eddington ratio, is the dominant factor in launching powerful jets and thus determining the radio loudness of active galactic nuclei (AGN). Most AGN…

High Energy Astrophysical Phenomena · Physics 2015-06-12 Marek Sikora , Mitchell C. Begelman

Active galactic nuclei (AGNs) are occasionally seen in pairs, suggesting that tidal encounters are responsible for the accretion of material by both central supermassive black holes (BHs). In Paper I of this series, we selected a sample of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Xin Liu , Yue Shen , Michael A. Strauss

We report the detection of ubiquitous powerful nuclear outflows in massive (> 10^11 Msun) z~2 star-forming galaxies (SFGs), which are plausibly driven by an Active Galactic Nucleus (AGN). The sample consists of the eight most massive SFGs…

We investigate the origin of the intrinsic scatter in the correlation between black hole mass (MBH) and bulge luminosity [L(bulge)] in a sample of 45 massive, local (z < 0.35) type~1 active galactic nuclei (AGNs). We derive MBH from…

We investigate the local supermassive black hole (SMBH) density function and relative mass accretion rates of all active galactic nuclei (AGNs) identified in a volume-limited sample of infrared (IR) bright galaxies (L_IR > 3 x 10^9 L_sun)…

Astrophysics of Galaxies · Physics 2015-05-18 Andy D. Goulding , David M. Alexander , Bret D. Lehmer , James R. Mullaney

There is mounting evidence that supermassive black holes form and grow in bulgeless galaxies. However, a robust determination of the fraction of AGNs in bulgeless galaxies, an important constraint to models of supermassive black hole seed…

Astrophysics of Galaxies · Physics 2016-08-17 S. Satyapal , N. J. Secrest , B. Rothberg , J. O'Connor , S. L. Ellison , R. C. Hickox , A. Constantin , M. Gliozzi , J. L. Rosenberg

We investigate the relation of black hole mass versus host stellar mass and that of mass accretion rate versus star formation rate (SFR) in moderately luminous ($\log L_{\rm bol} \sim 44.5-46.5\ {\rm erg\ s^{-1}}$), X-ray selected…

Astrophysics of Galaxies · Physics 2021-03-24 Kenta Setoguchi , Yoshihiro Ueda , Yoshiki Toba , Masayuki Akiyama

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…

We analyze a sample of 32 galaxies for which a dynamical estimate of the mass of the hot stellar component, M_bulge, is available. For each of these galaxies, we calculate the mass of the central black hole, M_BH, using the tight empirical…

Astrophysics · Physics 2009-10-31 David Merritt , Laura Ferrarese

There are strong suggestions that the disk-like accretion flow onto massive black hole in AGN is disrupted in its innermost part (10-100 Rg), possibly due to the radiation pressure instability. It may form a hot optically thin quasi…

Astrophysics · Physics 2009-10-31 B. Czerny , A. Abrassart , S. Collin-Souffrin , A. -M. Dumont

Observational studies have revealed a "downsizing" trend in black hole (BH) growth: the number densities of luminous AGN peak at higher redshifts than those of faint AGN. This would seem to imply that massive black holes formed before low…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Michaela Hirschmann , Rachel S. Somerville , Thorsten Naab , Andreas Burkert

High-redshift ($z\sim2-3$) galaxies accrete circumgalactic gas through cold streams. Recent high-resolution MHD simulations of these streams showed a significant amplification of the intergalactic magnetic field in the shear layer around…

Astrophysics of Galaxies · Physics 2024-11-20 Nicolas Ledos , Evangelia Ntormousi , Shinsuke Takasao , Kentaro Nagamine

There possibly was an AGN episode in the Galactic Centre about 6 Myr ago, powerful enough to produce the Fermi bubbles. We present numerical simulations of a possible scenario giving rise to an activity episode: a collision between a…

Astrophysics of Galaxies · Physics 2020-01-15 M. Tartėnas , K. Zubovas

Aims. In this paper we continue our study of density cusps that may contain central black holes. Methods. We recall our attempts to use distribution functions with a memory of self-similar relaxation, but mostly they apply only in…

Astrophysics of Galaxies · Physics 2015-05-14 Morgan Le Delliou , Richard N. Henriksen , Joseph D. Macmillan

We present the black hole mass--bulge velocity dispersion relation for a complete sample of 75 soft X-ray selected AGNs. We find that the AGNs with highest accretion rates relative to Eddington lie below the \mbh--\sig\ relation of broad…

Astrophysics · Physics 2009-11-10 Smita Mathur , Dirk Grupe

We use cosmological hydrodynamical simulations to show that a significant fraction of the gas in high redshift rare massive halos falls nearly radially to their very centre on extremely short timescales. This process results in the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Yohan Dubois , Christophe Pichon , Martin Haehnelt , Taysun Kimm , Adrianne Slyz , Julien Devriendt , Dmitry Pogosyan

Accretion in the nuclei of active galaxies may occur chaotically. This can produce accretion discs which are counter-rotating or strongly misaligned with respect to the spin of the central supermassive black hole (SMBH), or the axis of a…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Chris Nixon , Andrew King , Daniel Price