The XMM deep survey in the CDF-S. VIII. X-ray properties of the two brightest sources

Abstract

We present results from the deep XMM-Newton observations of the two brightest X-ray sources in the Chandra Deep Field South (CDFS), PID 203 (z = 0.544) and PID 319 (z = 0.742). The long exposure of 2.5 Ms over a 10 year period (net 4 yr with a 6 yr gap) makes it possible to obtain high quality X-ray spectra of these two Type I AGN with X-ray luminosity of 1044 erg s-1, which is the typical luminosity for low-redshift PG quasars, and track their X-ray variability both in flux and spectral shape. Both sources showed X-ray flux variability of ~10−20% in rms, which is similar in the soft (0.5−2 keV) and hard (2−7 keV) bands. PID 203, which has evidence for optical extinction, shows modest amount of absorption (NH≤ 1 × 1021 cm-2) in the X-ray spectrum. Fe K emission is strongly detected in both objects with EW ~ 0.2 keV. The lines in both objects are moderately broad and exhibit marginal evidence for variability in shape and flux, indicating that the bulk of the line emission comes from their accretion disks rather than distant tori.