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T. Urrutia (UC Davis / IGPP LLNL), M. Lacy (Spitzer Space Science Center), R. Becker, M. Gregg (UC Davis / IGPP LLNL), D. Helfand (Columbia University)
We have selected a sample of 12 dust-reddened quasars with 0.4 < z < 2.21 and reddenings in the range 0.15 < E(B-V) < 1.7, using a combination of the 2MASS near-infrared survey, the FIRST radio survey and the Palomar Sky Survey plates. We obtained ACIS-S X-ray spectra of these quasars, estimated the column densities towards them, and hence obtained the gas:dust ratios in the material obscuring the quasar. Even though there is no obvious correlation between the X-ray determined column densities of our sources and their optical color or reddening, all of the sources show absorbed X-ray spectra. When we correct the luminosity for absorption, they can be placed among luminous 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. There is a hint that the mean spectral slope of the red quasar is higher than that of normal, unobscured quasars, which could be an indication for higher accretion rates and/or an evolutionary effect. We compare our results to other X-ray observations of red quasars. We investigate the number density of these sources compared to type 2 AGN based on the X-ray background and estimate how many moderate luminosity red quasars may be found in deep X-ray fields.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.