Red Optical Quasars are X-ray Blue Quasars

Abstract

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.

Additional details