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We present the identification and analysis of an unbiased sample of AGN that lie within the local galaxy population. Using the MPA-JHU catalogue (based on SDSS DR8) and 3XMM DR7 we define a parent sample of 25,949 local galaxies ($z \leq…

Astrophysics of Galaxies · Physics 2021-12-15 Keir L. Birchall , M. G. Watson , J. Aird , R. L. C. Starling

We constrain the intrinsic Eddington ratio (\lamEdd ) distribution function for local AGN in bins of low and high obscuration (log NH <= 22 and 22 < log NH < 25), using the Swift-BAT 70-month/BASS DR2 survey. We interpret the fraction of…

The massive black holes in most faint active galactic nuclei (AGNs) and even normal galaxies are still accreting gases, though their accretion rates are very low. Radiatively inefficient accretion flows (RIAFs) are supposed in these faint…

Astrophysics · Physics 2011-02-11 Xinwu Cao

The cosmological evolution of Active Galactic Nuclei (AGN) is important for understanding the mechanism of accretion onto supermassive black holes, and the related evolution of the host galaxy. In this work, we include objects with very low…

Astrophysics of Galaxies · Physics 2015-05-13 S. I. Raimundo , A. C. Fabian

To optimally identify candidates of the Compton-thick (CT) active galactic nuclei (AGN) that contribute to the unresolved X-ray background in infrared surveys, a tracer of column density is desirable in addition to an AGN indicator. In a…

Cosmology and Nongalactic Astrophysics · Physics 2011-10-19 K. M. Dasyra , I. Georgantopoulos , A. Pope , M. Rovilos

We have used XMM-Newton to observe six Lyman Break Analogs (LBAs): members of the rare population of local galaxies that have properties that are very similar to distant Lyman Break Galaxies. Our six targets were specifically selected…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Jianjun Jia , Andrew Ptak , Timothy M. Heckman , Roderik A. Overzier , Ann Hornschemeier , Stephanie M. LaMassa

We present a unification model for a clumpy obscurer in active galactic nuclei (AGN) and investigate the properties of the resulting X-ray spectrum. Our model is constructed to reproduce the column density distribution of the AGN population…

High Energy Astrophysical Phenomena · Physics 2019-09-04 Johannes Buchner , Murray Brightman , Kirpal Nandra , Robert Nikutta , Franz E. Bauer

X-ray surveys of active galactic nuclei (AGNs) provide direct constraints on the properties of individual AGNs, such as their emission, obscuration, and accretion rate. Previous AGN population synthesis models have not addressed such…

High Energy Astrophysical Phenomena · Physics 2026-05-19 D. Gerolymatou , S. Paltani , C. Ricci , T. T. Ananna

Changing-look active galactic nuclei (CLAGNs) show the disappearance and reappearance of broad emission lines in a few years, which challenges the orientation-based AGN unification model. We reduce the X-ray data for five well-studied…

High Energy Astrophysical Phenomena · Physics 2022-06-07 Hao Liu , Qingwen Wu , Bing Lyu

We combine data from two all-sky surveys in order to study the connection between the infrared and hard X-ray (>10keV) properties for local active galactic nuclei (AGN). The Swift/Burst Alert Telescope all-sky survey provides an unbiased,…

We present a new implementation of the GAlaxy Evolution and Assembly (GAEA) semi-analytic model, that features an improved modelling of the process of cold gas accretion onto supermassive black hole (SMBHs), derived from both analytic…

The nature of the putative torus and the outer geometry of active galactic nuclei (AGN) are still rather unknown and the subject of active research. Improving our understanding of them is crucial for developing a physical picture for the…

Astrophysics of Galaxies · Physics 2021-09-29 Christos Panagiotou , Roland Walter , Stephane Paltani

We present the multi-epoch monitoring with NuSTAR and XMM-Newton of NGC 1358, a nearby Seyfert 2 galaxy whose properties made it a promising candidate X-ray changing look AGN, i.e., a source whose column density could transition from its…

Bolometric luminosities and Eddington ratios of both X-ray selected broad-line (Type-1) and narrow-line (Type-2) AGN from the XMM-Newton survey in the COSMOS field are presented. The sample is composed by 929 AGN (382 Type-1 AGN and 547…

X-ray observations provide a powerful tool to probe the central engines of active galactic nuclei (AGN). A hard X-ray continuum is produced from deep within the accretion flow onto the supermassive black hole, and all optically thick…

High Energy Astrophysical Phenomena · Physics 2019-08-14 C. Reynolds , Y. Ueda , H. Awaki , L. Gallo , P. Gandhi , Y. Haba , T. Kawamuro , S. LaMassa , A. Lohfink , C. Ricci , F. Tazaki , A. Zoghbi

3C 223 is a radio loud, Type 2 quasar at $z=0.1365$ with an intriguing XMM-Newton spectrum that implicated it as a rare, Compton-thick ($N_{\rm H} \gtrsim 1.25 \times 10^{24}$ cm$^{-2}$) active galactic nucleus (AGN). We obtained…

High Energy Astrophysical Phenomena · Physics 2023-03-01 Stephanie M. LaMassa , Tahir Yaqoob , Panayiotis Tzanavaris , Poshak Gandhi , Timothy Heckman , George Lansbury , Aneta Siemiginowska

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 present the first study of an Iwasawa-Taniguchi/X-ray Baldwin effect for Compton-thick active galactic nuclei (AGN). We report a statistically significant anti-correlation between the rest-frame equivalent width (EW) of the narrow core…

Astrophysics of Galaxies · Physics 2018-04-25 Peter G. Boorman , Poshak Gandhi , Mislav Balokovic , Murray Brightman , Fiona Harrison , Claudio Ricci , Daniel Stern

We report on Chandra X-ray observations of four candidate low-mass black hole (<10^6Msun) active galactic nuclei (AGNs) that have the estimated Eddington ratios among the lowest (~10^(-2)) found for this class. The aims are to validate the…

Astrophysics of Galaxies · Physics 2015-06-18 W. Yuan , H. Zhou , L. Dou , X. -B. Dong , X. Fan , T. -G. Wang

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…

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