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Related papers: SHEEP: the ASCA 5-10 keV survey

200 papers

Results are presented on the X-ray properties of 9 high-redshift (1.2 < z < 3.4) radio-loud quasars (RLQs) observed by ASCA (10 observations) and ROSAT (11 observations, for a subset of 6 quasars). New ASCA observations of S5 0014+81 (z =…

Astrophysics · Physics 2016-08-30 M. Cappi , M. Matsuoka , A. Comastri , W. Brinkmann , M. Elvis , G. G. C. Palumbo , C. Vignali

We present a 2 - 10 keV ASCA observation of the field around the soft gamma repeater SGR1627-41. A quiescent X-ray source was detected in this observation whose position was consistent both with that of a recently discovered BeppoSAX X-ray…

Hard X-ray observations are the most efficient way to discriminate accretion-powered sources from star-light. Furthermore, hard X-rays are less affected than other bands by obscuration. For these reasons the advent of imaging instruments…

Astrophysics · Physics 2009-11-10 Fabrizio Fiore

We have constrained the extragalactic source count distributions over a broad range of X-ray fluxes and in various energy bands to test whether the predictions from X-ray background synthesis models agree with the observational constraints…

We present a spectroscopic study of 41 hard X-ray sources detected serendipitously with high significance (> 5 sigma in the 2-10 keV band) in seven EPIC performance/verification phase observations. The large collecting area of EPIC allows…

Astrophysics · Physics 2009-11-07 E. Piconcelli , M. Cappi , L. Bassani , F. Fiore , G. DiCocco , J. B. Stephen

GRS 1758-258 is one of the few persistent hard X-ray emitters (E>100 keV) in the Galaxy. Using the ASCA satellite, we have obtained the first detailed data on GRS 1758-258 in the 1-10 keV range, where previous observations were affected by…

Astrophysics · Physics 2009-10-28 S. Mereghetti , D. I. Cremonesi , F. Haardt , T. Murakami , T. Belloni , A. Goldwurm

We have discovered four AGN in the ROSAT all-sky-survey data with very steep X-ray spectra. We apply several models to these X-ray spectra with emphasis on warm absorber models which give an adequate description of the data. We report on…

Astrophysics · Physics 2007-05-23 J. Greiner , R. Danner , N. Bade , G. A. Richter , P. Kroll , S. Komossa

The EPIC detectors on XMM-Newton provide the most sensitive broad band (0.3-12 keV) X-ray spectra to date. Observations of 6 Seyfert 1 galaxies, covering a wide luminosity range, are examined with the aim of identifying the primary X-ray…

Astrophysics · Physics 2007-05-23 Ken Pounds , James Reeves

We present Suzaku observations of five hard X-ray selected nearby Seyfert 2 galaxies. All the sources were clearly detected with the pin Hard X-ray Detector up to several tens of keV, allowing for a fairly good characterization of the…

High Energy Astrophysical Phenomena · Physics 2015-05-19 A. Comastri , K. Iwasawa , R. Gilli , C. Vignali , P. Ranalli , G. Matt , F. Fiore

We present the spectral energy distributions (SEDs) of a hard X-ray selected sample. The sample contains 136 sources with F(2-10 keV)>10^-14 erg/cm^2/s and 132 are AGNs. The sources are detected in a 1 square degree area of the…

Detection of absorbed active galactic nuclei and their properties remains an elusive and important problem in understanding the evolution and activation of black holes. With the very hard X-ray survey conducted by Swift's Burst Alert…

High Energy Astrophysical Phenomena · Physics 2015-06-03 Lisa M. Winter

We have attempted to analyse all the available data taken by XMM-Newton as it slews between targets. This slew survey, the resultant source catalogue and the analysis procedures used are described in an accompanying paper. In this letter we…

Astrophysics · Physics 2015-06-24 Andrew Read , Richard Saxton , Pilar Esquej , Michael Freyberg , Bruno Altieri

We present the Swift X-ray Cluster Survey (SWXCS) catalog obtained using archival data from the X-ray telescope (XRT) on board the Swift satellite acquired from 2005 to 2012, extending the first release of the SWXCS. The catalog provides…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-16 Teng Liu , Paolo Tozzi , Elena Tundo , Alberto Moretti , Piero Rosati , Jun-Xian Wang , Gianpiero Tagliaferri , Sergio Campana , Mauro Giavalisco

In this work we present the first of two papers devoted to the study of the X-ray spectral characteristics of Seyfert 1 galaxies in the Piccinotti sample. In particular we analyse here the BeppoSAX broad band (0.1-100 keV) data of 4 objects…

Astrophysics · Physics 2009-11-10 A. Quadrelli , A. Malizia , L. Bassani , G. Malaguti

AXIS (An XMM-Newton International Survey) is a survey of 36 high Galactic latitude XMM-Newton observations covering 4.8 deg2 and containing 1433 serendipitous X-ray sources detected with 5-sigma significance. We have studied the X-ray…

We present preliminary results from the first 3 months of the Swift BAT high galactic latitude survey in the 14--195 keV band. The survey reaches a flux of \~10^{-11} erg/cm^2/s and has ~2.7' (90% confidence) positional uncertainties for…

Astrophysics · Physics 2009-11-13 C. B. Markwardt , J. Tueller , G. K. Skinner , N. Gehrels , S. D. Barthelmy , R. F. Mushotzky

The ROSAT Ultradeep HRI survey in the Lockman Hole contains a complete sample of 91 X-ray sources with fluxes in the 0.5-2 keV band larger than 1.2 times 10e-15 erg cm-2 s-1, where over about 75 per cent of the sources are quasars or…

We present the first results on the identifications of a medium sensitivity survey (X-ray flux limit 2E-14 erg/cm2/s in the 0.5-4.5 keV band) at high galactic latitude (|b|>20 deg) carried out with the XMM-Newton X-ray observatory within…

We discuss the X-ray, optical and radio properties of AX J0843+2942, a high luminosity Type 2 AGN found in the ASCA Hard Serendipitous Survey. The X-ray spectrum is best described by an absorbed power-law model with photon index of Gamma =…

We present a detailed spectral analysis of point-like X-ray sources in the XMM-COSMOS field. Our sample of 135 sources only includes those that have more than 100 net counts in the 0.3-10 keV energy band and have been identified through…

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