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We present ASCA X-ray results on two S0 galaxies, NGC 3065 and NGC 4203. In both galaxies, we detected hard X-ray emission from a point-like source at the nucleus. Single power law model having a photon index of 1.8 well described the…

We investigated the correlation between nuclear/circumnuclear starbursts around the active galactic nuclei (AGNs) and the AGN activities for 43 Seyfert galaxies in the CfA and 12 micron samples. We found that circumnuclear starburst…

Astrophysics · Physics 2009-11-13 Yasuyuki Watabe , Nozomu Kawakatu , Masatoshi Imanishi

We study the hard-X-ray spectral properties of ten highly luminous radio-quiet (RQ) active galactic nuclei (AGNs) at z=1.3-3.2, including new XMM-Newton observations of four of these sources. We find a significant correlation between the…

Astrophysics · Physics 2009-11-13 Ohad Shemmer , W. N. Brandt , Hagai Netzer , Roberto Maiolino , Shai Kaspi

We investigate the relationship between the present day optical luminosity function of galaxies and the X-ray luminosity function of Seyfert 1s to determine the fraction of galaxies which host Seyfert 1 nuclei and their Eddington ratios.…

Astrophysics · Physics 2009-11-07 M. J. Page

We present an analysis of the optical nuclear spectra from the active galactic nuclei (AGN) in a sample of giant low surface brightness (GLSB) galaxies. GLSB galaxies are extreme late type spirals that are large, isolated and poorly evolved…

Astrophysics of Galaxies · Physics 2017-08-23 Smitha Subramanian. , Ramya. S. , Mousumi Das. , Koshy George. , T. Sivarani , T. P. Prabhu

We have used the VLBA at 5 GHz to observe all galaxies with nuclear radio flux densities above 3.5 mJy found in a VLA survey at 15 GHz of a sample of nearby LINER galaxies. All galaxies were detected revealing high brightness temperature…

Astrophysics · Physics 2009-10-31 Heino Falcke , Neil M. Nagar , Andrew S. Wilson , James S. Ulvestad

[ABRIDGED] We recently presented evidence of a connection between the brightness profiles of nearby early-type galaxies and the properties of the AGN they host. The radio loudness of the AGN appears to be univocally related to the host's…

Astrophysics · Physics 2009-11-13 Alessandro Capetti , Barbara Balmaverde

The active galactic nuclei X-ray luminosity function traces actively accreting supermassive black holes and is essential for the study of the properties of the active galactic nuclei (AGN) population, black hole evolution, and galaxy-black…

I summarize the main observational properties of low-luminosity AGNs in nearby galaxies to argue that they are the high-mass analogs of black hole X-ray binaries in the "low/hard" state. The principal characteristics of low-state AGNs can…

Astrophysics · Physics 2009-11-11 Luis C. Ho

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

(Abridged) We present the results from new 15 ks Chandra-ACIS and 4.9 GHz Very Large Array observations of 13 galaxies hosting low luminosity AGN. This completes the multiwavelength study of a sample of 51 nearby early-type galaxies…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Preeti Kharb , A. Capetti , D. J. Axon , M. Chiaberge , P. Grandi , A. Robinson , G. Giovannini , B. Balmaverde , D. Macchetto , R. Montez

Active Galactic Nuclei (AGN) represent the growth phases of the supermassive black holes in the center of almost every galaxy. Powerful, highly ionized winds, with velocities $\sim 0.1- 0.2c$ are a common feature in X--ray spectra of…

Astrophysics of Galaxies · Physics 2015-09-23 Andrew King , Ken Pounds

The X-ray luminosity function (XLF) of galaxies is dominated by AGN (classified by their optical spectra) above Lx=10**42 erg/s, below this value by normal galaxies. The X-ray flux of AGN at low X-ray luminosity therefore contains…

Astrophysics · Physics 2007-05-23 I. Lehmann , G. Hasinger , A. D. Schwope , Th. Boller

In a matched sample of Seyfert and quiescent galaxies we simultaneously probe the stellar and molecular gas kinematics from 1 kpc down to 50 pc with the aim of identifying the dynamical processes dictating black hole accretion rates. This…

We observed the nearby galaxy M~51 (NGC 5194) with BeppoSAX. The X-ray properties of the nucleus below 10 keV are almost the same as the ASCA results regarding the hard component and the neutral Fe K$\alpha$ line, but the intensity is about…

Astrophysics · Physics 2009-11-06 Yasushi Fukazawa , Naoko Iyomoto , Aya Kubota , Yukari Matsumoto , Kazuo Makishima

We present an estimate of the space density of Active Galactic Nuclei (AGN) at z=3. Combining deep X-ray data with Lyman Break Galaxy (LBG) colour-selection in the rest-frame UV makes for highly efficient identification of AGN in a narrow…

Astrophysics · Physics 2009-11-10 K. Nandra , E. S. Laird , C. C. Steidel

We present the results of a search for nuclear X-ray activity in nearby galaxies using Chandra archival data in a sample of 62 galaxies from the Spitzer Infrared Nearby Galaxy Survey (SINGS). We detect 37 nuclear X-ray sources; seven of…

Astrophysics of Galaxies · Physics 2015-05-20 Catherine J. Grier , Smita Mathur , Himel Ghosh , Laura Ferrarese

(abbreviated): This paper presents the results of a high resolution radio imaging survey of all known (96) low-luminosity active galactic nuclei (LLAGNs) at D<19Mpc. We find that almost half of all LINERs and low-luminosity Seyferts have…

Astrophysics · Physics 2009-11-07 N. M. Nagar , H. Falcke , A. S. Wilson , J. S. Ulvestad

A fraction of active galactic nuclei do not show the classical Seyfert-type signatures in their optical spectra, i.e. they are optically "elusive". X-ray observations are an optimal tool to identify this class of objects. We combine new…

We present the latest results of a semi-analytic model of galaxy formation, "New Numerical Galaxy Catalogue", which is combined with large cosmological N-body simulations. This model can reproduce statistical properties of galaxies at z <…

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