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Related papers: Hot dust in two hard Chandra X-ray sources

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We present the first results of our optical spectroscopy program aimed to provide redshifts and identifications for the X-ray sources in the Extended Chandra Deep Field South. A total of 339 sources were targeted using the IMACS…

Using a radiative transfer code (DUSTY) parameters of the circumstellar dust shells of 15 hot post-AGB stars have been derived. Combining the optical, near and far-infrared (ISO, IRAS) data of the stars, we have reconstructed their spectral…

Astrophysics · Physics 2007-05-23 G. Sarkar Nee Gauba , M. Parthasarathy

We explore the relationship between the hard X-ray and sub-mm populations using deep Chandra observations of a large, contiguous SCUBA survey. In agreement with other recent findings, we confirm that the direct overlap is small. Of the 17…

Deep Chandra X-ray exposures provide an efficient route for locating optically faint active galactic nuclei (AGN) at high redshifts. We use deep multicolor optical data to search for z>5 AGN in the 2 Ms X-ray exposure of the Chandra Deep…

We present SCUBA-2 850um submillimetre (submm) observations of the fields of 10 dusty, luminous galaxies at z ~ 1.7 - 4.6, detected at 12um and/or 22um by the WISE all-sky survey, but faint or undetected at 3.4um and 4.6um; dubbed hot,…

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

The 13hr XMM-Newton/Chandra deep survey is the first of two extremely deep XMM-Newton fields observed by the XMM-OM consortium. A 120 ks Chandra mosaic, covering 0.2 square degrees, provides sensitive, confusion-free point source detection…

We present a comprehensive analysis of 475 ks (438 ks unpublished & 37 ks archival) XMM-Newton/EPIC-pn observation of a nearby, highly inclined, star-forming, luminous infrared galaxy NGC 3221 through spatial, temporal, and spectral…

Astrophysics of Galaxies · Physics 2025-11-25 Sanskriti Das , Smita Mathur , Bret D. Lehmer , Steven W. Allen , Yair Krongold , Anjali Gupta

Obscured AGN represent a significant fraction of the entire AGN population, especially at high redshift (~70% at z=3--5). They are often characterized by the presence of large gas and dust reservoirs that are thought to sustain and possibly…

We present the analysis of four NuSTAR observations of the luminous infrared galaxy merger NGC 6240, hosting a close pair of highly obscured active galactic nuclei (AGN). Over a period of about two years, the source exhibits hard X-ray…

High Energy Astrophysical Phenomena · Physics 2017-08-23 Emanuele Nardini

{\it Chandra} Galactic Center Survey detected $\sim 800$ X-ray point-like sources in the $2^{\circ} \times 0.8^{\circ}$ sky region around the Galactic Center. In this paper, we study the spatial and luminosity distributions of these sources…

Astrophysics · Physics 2014-10-13 J. F. Wu , S. N. Zhang , F. J. Lu , Y. K. Jin

We present observations of a sample of optically-faint, hard X-ray sources of the kind likely to be responsible for much of the hard X-ray background. We confirm that such sources are easily detected in the near-infrared, and find that they…

Astrophysics · Physics 2009-09-17 C. S. Crawford , A. C. Fabian , P. Gandhi , R. J. Wilman , R. M. Johnstone

We present a multi-wavelength study of seven AGN at spectroscopic redshift >2.5 in the 7 Ms Chandra Deep Field South, selected to have good FIR/sub-mm detections. Our aim is to investigate the possibility that the obscuration observed in…

Astrophysics of Galaxies · Physics 2019-04-03 C. Circosta , C. Vignali , R. Gilli , A. Feltre , F. Vito , F. Calura , V. Mainieri , M. Massardi , C. Norman

We report optical spectroscopic identifications of 10 hard (2-10 keV) X-ray selected sources discovered by Chandra. The X-ray flux of the sources ranges between 1.5 and 25 x 10-14 cgs, the lower value being 3 times fainter than in previous…

Astrophysics · Physics 2009-10-31 F. Fiore , F. La Franca , C. Vignali , A. Comastri , G. Matt , G. C. Perola , M. Cappi , M. Elvis , F. Nicastro

The first systematic study of the serendipitous X-ray source density around 10 high z (0.24<z<1.2) clusters performed with Chandra is presented. A factor \~2 overdensity has been found in 4 cluster fields. The result is statistically highly…

Astrophysics · Physics 2007-05-23 N. Cappelluti , M. Cappi , M. Dadina , G. Malaguti , M. Branchesi , V. D'Elia , G. G. C. Palumbo

The Chandra Deep Field is the region of the sky with the highest concentration of X-ray data available: 4Ms of Chandra and 3Ms of XMM data, allowing excellent quality spectra to be extracted even for faint sources. We take advantage of this…

We report the detection of six discrete, low-luminosity (Lx < 10^33 erg/s) X-ray sources, located within 12 arcsec of the center of the collapsed-core globular cluster M30 (NGC 7099), and a total of 13 sources within the half-mass radius,…

We report on the results of observations of hard X-ray sources in the Galactic plane with the Chandra X-ray Observatory. The hard X-ray IGR sources were discovered by the INTEGRAL satellite, and the goals of the Chandra observations are to…

Astrophysics · Physics 2009-11-13 John A. Tomsick , Sylvain Chaty , Jerome Rodriguez , Roland Walter , Philip Kaaret

First indications of the warm/hot intergalactic medium, tracing out the large scale structure of the universe, have been obtained in sensitive Chandra and XMM-Newton high resolution absorption line spectroscopy of bright blazars. High…

Astrophysics · Physics 2007-05-23 Guenther Hasinger

Chandra X-ray Observatory has revealed X-ray cavities in many nearby cooling flow clusters. The cavities trace feedback from the central active galactic nulceus (AGN) on the intracluster medium (ICM), an important ingredient in stabilizing…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 L. Birzan , D. A. Rafferty , B. R. McNamara , P. E. J. Nulsen , M. W. Wise