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Red Optical Quasars are X-ray Blue Quasars

Urrutia, T. and Lacy, M. and Becker, R. and Gregg, M. (2005) Red Optical Quasars are X-ray Blue Quasars. In: Growing Black Holes: Accretion in a Cosmological Context. ESO Astrophysics Symposia. Springer , Berlin, pp. 142-143. ISBN 978-3-540-25275-7.

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We have selected a sample of 12 dust-reddened quasars with extremely red colors, reddenigs and redshifts in the range of 0.4 < z < 2.21 using a combination of various surveys in the radio, infrared and optical. We obtained Chandra observations of these quasars, estimated the column densities towards them, and hence obtained the gas:dust ratios in the material obscuring the quasar. The reddenings do not correlate with the column densities or the hardness ratios in the X-rays. All of the sources show absorbed X-ray spectra, although none of them present Seyfert 2 typical column densities. When we correct the luminosity for absorption, they can be placed among high luminosity quasars, therefore our objects seem to be the high luminosity analogues of the sources contributing to the X-ray background seen in deep X-ray observations.

Item Type:Book Section
Related URLs:
URLURL TypeDescription ReadCube access
Urrutia, T.0000-0001-6746-9936
Lacy, M.0000-0002-3032-1783
Additional Information:© 2005 Springer-Verlag Berlin Heidelberg. First Online: 22 December 2005.
Subject Keywords:Column Density; Lawrence Livermore National Laboratory; High Luminosity; Spectral Slope; Hardness Ratio
Series Name:ESO Astrophysics Symposia
Record Number:CaltechAUTHORS:20191209-153753984
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Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:100252
Deposited By: Tony Diaz
Deposited On:09 Dec 2019 23:47
Last Modified:16 Nov 2021 17:52

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