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Related papers: Heavy obscuration in X-ray weak AGNs

200 papers

Aims: We present a near-infrared spectral atlas of 47 active galactic nuclei (AGN), of all degrees of activity, in the wavelength interval of 0.8-2.4 microns, including the fluxes of the observed emission lines. We analyze the spectroscopic…

Astrophysics · Physics 2009-11-11 R. Riffel , A. Rodriguez-Ardila , M. G. Pastoriza

We report the first simultaneous measure of the X-ray broadband (0.1--200 keV) continuum and of the iron K-alpha fluorescent line profile in the Seyfert 1 galaxy MCG-6-30-15. Our data confirms the ASCA detection of a skewed and redshifted…

We have been carrying out a successful observational programme targeted at finding the highly obscured quasars that are thought to be the main contributors to the hard X-ray background. Out of 56 sources so far studied with optical and…

Astrophysics · Physics 2015-06-24 C. S. Crawford , P. Gandhi , A. C. Fabian

We investigate the nature of the faint X-ray source population through X-ray spectroscopy and variability analyses of 136 AGN detected in the 2 Ms Chandra Deep Field-North survey with > 200 background-subtracted 0.5-8.0 keV counts…

With recent Chandra observations, at least 60% of the 2-10 keV background is now resolved into discrete sources. Here we present deep optical, NIR, submm, and 20 cm (radio) images, as well as high-quality optical spectra, of a complete…

Astrophysics · Physics 2009-09-25 A. J. Barger , L. L. Cowie , R. F. Mushotzky , E. A. Richards

We present new BeppoSAX LECS, MECS, and PDS observations of five lobe-dominated, broad-line active galactic nuclei selected from the 2 Jy sample of southern radio sources. These include three radio quasars and two broad-line radio galaxies.…

Astrophysics · Physics 2009-10-30 R. Morganti , P. Padovani , J. Siebert , A. Cimatti , C. N. Tadhunter , F. Vagnetti

We present an analysis of spectrum and variability of the bright reddened narrow line Seyfert 1 galaxy Was~61 using 90 ks archival {\it XMM-Newton} data. The X-ray spectrum in 0.2-10 keV can be characterized by an absorbed power-law plus…

High Energy Astrophysical Phenomena · Physics 2016-03-11 Liming Dou , Ting-Gui Wang , Yanli Ai , Weimin Yuan , Hongyan Zhou , Xiao-Bo Dong

According to the unified model, the differences observed in different classes of AGN are due to anisotropic obscuration. This implies that in the hard X-rays, at energies where the radiation can pierce the obscuring material, the average…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-31 C. Ricci , R. Walter , T. J. -L. Courvoisier

The Seyfert 1 galaxy, Ark 120, is a prototype example of the so-called class of bare nucleus AGN, whereby there is no known evidence for the presence of ionized gas along the direct line of sight. Here deep ($>400$ ks exposure), high…

High Energy Astrophysical Phenomena · Physics 2016-09-21 James Reeves , Delphine Porquet , Valentina Braito , Emanuele Nardini , Andrew Lobban , Jane Turner

We combine emission line and X-ray luminosities for 45 sources from the Chandra Deep Field South (CDF-S), and seven HELLAS sources, to obtain a new sample of 52 X-ray selected type-II active galactic nuclei (AGNs). Eighteen of our sources…

Astrophysics · Physics 2009-11-11 Hagai Netzer , V. Mainieri , P. Rosati , Benny Trakhtenbrot

We summarize the multiwavelength properties of X-ray sources detected in the 80 ks XMM-Newton observation of the Groth-Westphal Strip. We find 23 XMM-Newton sources within the WFPC2 fields. Ten spectroscopic redshifts are available from the…

We present broad band Suzaku}observations of a small sample of hard X-ray selected (> 10 keV), nearby Seyfert 2 galaxies and discuss the results in the context of AGN unified model. We also review the issues related to the space density of…

Cosmology and Nongalactic Astrophysics · Physics 2009-10-07 A. Comastri , K. Iwasawa , R. Gilli , C. Vignali , P. Ranalli

We present a complete analysis of the hard X-ray (2-10 keV) properties of the Seyfert galaxy NGC 1365, based on a 60 ks XMM-Newton observation performed in January 2004. The two main results are: 1) We detect an obscuring cloud with…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-11 G. Risaliti , G. Miniutti , G. Fabbiano , M. Salvati , A. Baldi , V. Braito , S. Bianchi , G. Matt , J. Reeves , R. Soria , A. Zezas

Deep X-ray surveys have shown that the cosmic X-ray background (XRB) is largely due to the accretion onto supermassive black holes, integrated over the cosmic time. These surveys have resolved more than 80% of the 0.1-10 keV X-ray…

Astrophysics · Physics 2011-06-30 Guenther Hasinger , the CDF-S team

Our goal is to probe the populations of obscured and unobscured AGN investigating their optical-IR and X-ray properties as a function of X-ray flux, luminosity and redshift within a hard X-ray selected sample of 136 X-ray sources in the XMM…

(Abridged) We present a detailed broadband X-ray spectrum of NGC 4258, with the goal of precisely measuring the coronal luminosity and accretion flow properties of the AGN, and track any possible variation across two decades of…

High Energy Astrophysical Phenomena · Physics 2022-07-20 Alberto Masini , J. V. Wijesekera , Annalisa Celotti , Peter G. Boorman

We report a new sample of obscured active galactic nuclei (AGNs) selected from the XMM serendipitous source and AKARI point-source catalogs. We match X-ray sources with infrared (18 and 90 micron) sources located at |b|>10 deg to create a…

Astrophysics of Galaxies · Physics 2015-11-18 Yuichi Terashima , Yoshitaka Hirata , Hisamitsu Awaki , Shinki Oyabu , Poshak Gandhi , Yoshiki Toba , Hideo Matsuhara

We report on ROSAT and ASCA observations of the LINER NGC1052, which is the first one where broad optical lines in polarized light have been observed. The 2-10 keV spectrum is very flat, with an observed photon index (Gamma) ~0.1. A model…

Astrophysics · Physics 2009-10-31 M. Guainazzi , L. A. Antonelli

We use the 4Ms CDF-S survey to place direct X-ray constraints on the ubiquity of z~2 heavily obscured AGNs in K<22 BzK galaxies. Forty seven of the 222 BzK galaxies in the central region of the CDF-S are detected at X-ray energies, 11 of…

We present the results of X-ray spectral-timing analysis of a 90ks XMM-Newton observation of the nearby, broad line, early-type AGN NGC5273. The X-ray spectrum revealed the clear presence of a reflection component at high energies, with a…

High Energy Astrophysical Phenomena · Physics 2020-01-08 F. M. Vincentelli , G. Mastroserio , I. Mc Hardy , A. Ingram , M. Pahari