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Related papers: Re-evaluating the Local Compton-thick AGN Fraction

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We present a uniform broadband X-ray (0.5-100.0 keV) spectral analysis of 12 Swift/Burst Alert Telescope (BAT) selected Compton-thick ($\log N_{\mathrm{H}}/\mathrm{cm}^{-2} \geq 24$) Active Galactic Nuclei (CTAGNs) observed with Suzaku. The…

High Energy Astrophysical Phenomena · Physics 2018-02-14 Atsushi Tanimoto , Yoshihiro Ueda , Taiki Kawamuro , Claudio Ricci , Hisamitsu Awaki , Yuichi Terashima

We present the analysis of multiepoch observations of a set of 12 variable, Compton-thin, local (z<0.1) active galactic nuclei (AGN) selected from the 100-month BAT catalog. We analyze all available X-ray data from \chandra, \xmm, and…

Astrophysics of Galaxies · Physics 2023-10-18 N. Torres-Albà , S. Marchesi , X. Zhao , I. Cox , A. Pizzetti , M. Ajello , R. Silver

We analyse Compton-thick active galactic nuclei (CT AGNs), a heavily obscured subclass that challenges traditional X-ray diagnostics. Using 243 sources from the 70-Month \textit{SWIFT}/BAT catalogue (26 CT, 217 non-CT), we investigate their…

We investigate the population of high-redshift ($3\leq z < 6$) AGN selected in the two deepest X-ray surveys, the 7 Ms \textit{Chandra} Deep Field-South and 2 Ms \textit{Chandra} Deep Field-North. Their outstanding sensitivity and spectral…

We present analysis of spectral energy distributions (SEDs) from mid-infrared through X-ray of a sample of 420 hard X-ray selected, z-band and Spitzer/IRAC detected active galactic nuclei (AGN) and AGN candidates from the GOODS…

We report on an optical (SDSS) and X-ray (XMM) study of an optically selected sample of four dual AGN systems at projected separations of 30--60~kpc. All sources are detected in the X-ray band (0.3-10 keV); seven objects are optically…

We present X-ray spectral analyses for three Seyfert 2 active galactic nuclei, NGC 424, NGC 1320, and IC 2560, observed by NuSTAR in the 3-79 keV band. The high quality hard X-ray spectra allow detailed modeling of the Compton reflection…

Compton-thick active galactic nuclei (CT-AGNs), which are defined by column density $\mathrm{N_H} \geqslant 1.5 \times 10^{24} \ \mathrm{cm}^{-2}$, emit feeble X-ray radiation, even undetectable by X-ray instruments. Despite this, the X-ray…

Astrophysics of Galaxies · Physics 2025-05-28 Rui Zhang , Xiaotong Guo , Qiusheng Gu , Guanwen Fang , Jun Xu , Hai-Cheng Feng , Yongyun Chen , Rui Li , Nan Ding , Hongtao Wang

The X-ray color (hardness ratio) of optically undetected X-ray sources can be used to distinguish obscured active galactic nuclei (AGNs) at low and intermediate redshift from viable high-redshift (i.e., z>5) AGN candidates. This will help…

Astrophysics · Physics 2009-11-10 J. X. Wang , S. Malhotra , J. E. Rhoads , C. A. Norman

We present some results of the deepest extragalactic survey performed by the INTEGRAL satellite. The fraction of very absorbed AGN is quite large. The sharp decrease in the absorption fraction with X-ray luminosity observed at lower-energy…

Astrophysics of Galaxies · Physics 2009-06-25 S. Paltani , T. Dwelly , R. Walter , A. P. Marscher , S. G. Jorstad , I. M. McHardy , T. J. -L. Courvoisier

The evidence of a decrease with increasing luminosity of the fraction f_{abs} of absorbed and Compton-thin among X-ray (2-10 keV) selected AGN is observationally rather well supported, while that of an increase of f_{abs} with redshift is…

Astrophysics · Physics 2009-11-13 A. Lamastra , G. C. Perola , G. Matt

We present results on a search of heavily obscured active galaxies z>1.7 using the rest-frame 9-20 keV excess for X-ray sources detected in the deep XMM-CDFS survey. Out of 176 sources selected with the conservative detection criteria (>8…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 K. Iwasawa , R. Gilli , C. Vignali , A. Comastri , W. N. Brandt , P. Ranalli , F. Vito , N. Cappelluti , F. J. Carrera , S. Falocco , I. Georgantopoulos , V. Mainieri , M. Paolillo

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 aim to test a method of efficiently selecting X-ray obscured AGN in the 2XMM-Newton EPIC Serendipitous Source Catalogue. By means of a strong correlation established using the XMM-Newton Hard Bright Sample between the intrinsic…

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…

High Energy Astrophysical Phenomena · Physics 2015-10-07 Sergey Sazonov , Eugene Churazov , Roman Krivonos

Using the large multi-wavelength data set in the chandra/SWIRE Survey (0.6 square degrees in the Lockman Hole), we show evidence for the existence of highly obscured (Compton-thick) AGN, estimate a lower limit to their surface density and…

We present a detailed and self-consistent modeling of the cosmic X-ray background (XRB) based on the most up-to-date X-ray luminosity functions (XLF) and evolution of Active Galactic Nuclei (AGN). The large body of observational results…

Astrophysics · Physics 2009-11-11 Roberto Gilli , Andrea Comastri , Guenther Hasinger

The cosmic X-ray background (CXB) is dominated by the obscured and unobscured coronal light of active galactic nuclei (AGN). At energies below 10 keV, the CXB can be well explained by models taking into account the known AGN and the…

High Energy Astrophysical Phenomena · Physics 2025-02-03 Isaiah S. Cox , Núria Torres-Albà , Stefano Marchesi , Peter Boorman , Xiurui Zhao , Ross Silver , Marco Ajello , Indrani Pal

We investigate the possibility of using the ratio between the 2-10 keV flux and the [Ne V]3426 emission line flux (X/NeV) as a diagnostic diagram to discover heavily obscured, possibly Compton-Thick Active Galactic Nuclei (AGN) up to z~1.5.…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 R. Gilli , C. Vignali , M. Mignoli , K. Iwasawa , A. Comastri , G. Zamorani