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We present a selection technique to detect Compton-thick (CT) active galactic nuclei (AGNs) in the 3XMM/SDSS-DR7 cross-correlation. A subsample of 3481 X-ray sources that are detected in the hard band (2-8 keV) and have photometric…

星系天体物理 · 物理学 2023-09-27 Reham Mostafa , Matteo Guainazzi , Alaa Ibrahim

The dynamics and structure of toroidal obscuration around AGN remain uncertain and controversial. In this paper we extend earlier work on the dynamical role of infrared radiation pressure by adding the effects of two kinds of distributed…

天体物理学 · 物理学 2009-11-13 Jiming Shi , Julian H. Krolik

We present the results of a systematic, broadband X-ray spectral analysis of nearby active galactic nuclei (AGNs) with the X-ray clumpy torus model (XCLUMPY; Tanimoto et al. 2019). By adding 16 AGNs newly analyzed in this paper, we study…

高能天体物理现象 · 物理学 2021-01-20 Shoji Ogawa , Yoshihiro Ueda , Atsushi Tanimoto , Satoshi Yamada

Aims. We present a 0.2--200 keV broad-band study of absorbed AGN observed with INTEGRAL, XMM-Newton, Chandra and ASCA to investigate the continuum shape and the absorbing/reflecting medium properties. Methods. The sources are selected in…

天体物理学 · 物理学 2009-11-13 A. De Rosa , L. Bassani , P. Ubertini , F. Panessa , A. Malizia , A. J. Dean , R. Walter

The circumnuclear material around Active Galactic Nuclei (AGN) is one of the essential components of the obscuration-based unification model. However, our understanding of the circumnuclear material in terms of its geometrical shape,…

Most Active Galactic Nuclei (AGN) exhibit a narrow Fe Kalpha line at ~ 6.4 keV in the X-ray spectra, due to the fluorescent emission from cold material far from the inner accretion disk. Using XMM-Newton observations, Page et al. found that…

天体物理学 · 物理学 2009-11-11 P. Jiang , J. X. Wang , T. G. Wang

The narrow Fe K$\alpha$ line is one of the main signatures of the reprocessing of X-ray radiation from the material surrounding supermassive black holes, and it has been found to be omnipresent in the X-ray spectra of active galactic nuclei…

星系天体物理 · 物理学 2015-06-19 Claudio Ricci , Yoshihiro Ueda , Stephane Paltani , Kohei Ichikawa , Poshak Gandhi , Hisamitsu Awaki

We present the distributions of geometrical covering factors of active galactic nuclei (AGNs) dusty tori (f2) using an X-ray selected complete sample of 227 AGN drawn from the Bright Ultra-hard XMM-Newton Survey. The AGN have z from 0.05 to…

We present here a detailed X-ray spectral analysis of the AGN belonging to the XMM-Newton bright survey (XBS) that comprises more than 300 AGN up to redshift ~ 2.4. We performed an X-ray analysis following two different approaches: by…

宇宙学与河外天体物理 · 物理学 2015-05-27 A. Corral , R. Della Ceca , A. Caccianiga , P. Severgnini , H. Brunner , F. J. Carrera , M. J. Page , A. D. Schwope

A cornerstone of AGN unification schemes is the presence of an optically and geometrically thick dust torus. It provides the obscuration to explain the difference between type 1 and type 2 AGN. We investigate the influence of the dust…

天体物理学 · 物理学 2007-09-24 Sebastian F. Hoenig , Thomas Beckert

Due to their heavily obscured central engines, the growth rate of Compton-thick (CT) active galactic nuclei (AGN) is difficult to measure. A statistically significant correlation between the Eddington ratio, {\lambda}$_{Edd}$, and the X-ray…

Chandra and XMM surveys show that the fraction of obscured AGN decreases rapidly with increasing luminosity. Although this is usually explained by assuming that the covering factor of the central engine is much smaller at luminous QSOs, the…

天体物理学 · 物理学 2009-11-13 A. Akylas , I. Georgantopoulos

The all-sky hard X-ray survey performed by Swift/BAT allowed the detection of many heavily obscured Compton-thick AGN. In our previous work, we have identified more than 50 candidate Compton-thick AGN in the local Universe, corresponding to…

星系天体物理 · 物理学 2019-01-09 I. Georgantopoulos , A. Akylas

We present the systematic broadband X-ray spectral analysis of 52 Compton-thick ($24 \leq \log N_{\mathrm{H}}^{\mathrm{LOS}}/\mathrm{cm}^{-2}$) active galactic nucleus (CTAGN) candidates selected by the Swift/BAT all-sky hard X-ray survey…

高能天体物理现象 · 物理学 2022-06-29 Atsushi Tanimoto , Yoshihiro Ueda , Hirokazu Odaka , Satoshi Yamada , Claudio Ricci

We have combined the CLASXS Chandra survey in Lockman with the Spitzer SWIRE survey data to study the X-ray-infrared connection for AGN. The sample consists of 401 X-ray-sources, of which 306 are detected by Spitzer, and a further 257 AGN…

宇宙学与河外天体物理 · 物理学 2010-11-02 Michael Rowan-Robinson , Ivan Valtchanov , Kirpal Nandra

We present the first systematic broad-band X-ray study of super-Eddington accretion onto SMBHs with simultaneous {\it NuSTAR} and {\it XMM-Newton} or {\it Swift}/XRT observations of a sample of 8 super-Eddington accreting AGN with Eddington…

高能天体物理现象 · 物理学 2022-12-14 Alessia Tortosa , Claudio Ricci , Luis C. Ho , Francesco Tombesi , Pu Du , Kohei Inayoshi , Jian-Min Wang , Jinyi Shangguan , Ruancun Li

(Abridged) We present the results from the X-ray spectral analysis of high-z AGN in the CDFS, making use of the new 4Ms data set and new X-ray spectral models from Brightman & Nandra, which account for Compton scattering and the geometry of…

高能天体物理现象 · 物理学 2015-06-04 Murray Brightman , Yoshihiro Ueda

We use a sample of 151 local non-blazar AGN selected from the INTEGRAL all-sky hard X-ray survey to investigate if the observed declining trend of the fraction of obscured (i.e. showing X-ray absorption) AGN with increasing luminosity is…

高能天体物理现象 · 物理学 2015-10-07 Sergey Sazonov , Eugene Churazov , Roman Krivonos

Obscured AGN are fundamental to understand the history of Super Massive Black Hole growth and their influence on galaxy formation. However, the Compton-thick AGN (NH>1e24 cm^-2) population is basically unconstrained, with less than few…

宇宙学与河外天体物理 · 物理学 2015-05-20 P. Severgnini , A. Caccianiga , R. Della Ceca , V. Braito , C. Vignali , V. La Parola , A. Moretti

Heavily obscured active galactic nuclei (AGNs) play an important role in contributing to the cosmic X-ray background (CXRB). However, the AGNs found in deep X-ray surveys are often too weak to allow direct measurement of the column density…

高能天体物理现象 · 物理学 2015-05-20 Tahir Yaqoob , Kendrah D. Murphy