The Chandra Deep Field South: Optical Spectroscopy I
Abstract
We present the results of our spectroscopic follow-up program of the X-ray sources detected in the 942 ks exposure of the Chandra Deep Field South (CDFS). 288 possible counterparts were observed at the VLT with the FORS1/FORS2 spectrographs for 251 of the 349 Chandra sources (including three additional faint X-ray sources). Spectra and R-band images are shown for all the observed sources and R-K colours are given for most of them. Spectroscopic redshifts were obtained for 168 X-ray sources, of which 137 have both reliable optical identification and redshift estimate (including 16 external identifications). The R<24 observed sample comprises 161 X-ray objects (181 optical counterparts) and 126 of them have unambiguous spectroscopic identification. We introduce a new classification based solely on X-ray properties, HR and X-ray luminosity, consistent with the unified AGN model. This X-ray classification uncovers a large fraction of optically obscured, X-ray luminous AGNs missed by the classical optical classification.
Cite
@article{arxiv.astro-ph/0312324,
title = {The Chandra Deep Field South: Optical Spectroscopy I},
author = {G. P. Szokoly and J. Bergeron and G. Hasinger and I. Lehmann and L. Kewley and V. Mainieri and M. Nonino and P. Rosati and R. Giacconi and R. Gilli and R. Gilmozzi and C. Norman and M. Romaniello and E. Schreier and P. Tozzi and J. X. Wang and W. Zheng and A. Zirm},
journal= {arXiv preprint arXiv:astro-ph/0312324},
year = {2009}
}
Comments
Accepted for publication in ApJ supplement. Full version is available from http://www.mpe.mpg.de/~mainieri/cdfs_pub/