Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The ultra-deep XMM survey in the CDFS: X-ray spectroscopy of heavily
  obscured AGN   We present selected results on the X-ray spectroscopy of distant, obscured
AGN as obtained with the ultra-deep (~3 Ms) XMM-Newton survey in the Chandra
Deep Field South (CDF-S). One of the primary goals of the project is to
characterize the X-ray spectral properties of heavily obscured and
Compton-thick AGN over the range of redshifts and luminosities that are
relevant in terms of their contribution to the X-ray background. The ultra-deep
exposure, coupled with the XMM detector's spectral throughput, allowed us to
accumulate X-ray spectra for more than 100 AGN to investigate the absorption
distribution up to z~4.

34
The categories of this paper are: chem-ph
32
The categories of this paper are: atom-ph
33
The categories of this paper are: plasm-ph
7
The categories of this paper are: hep-th
14
The categories of this paper are: math-ph
8
The categories of this paper are: hep-ex
1
The categories of this paper are: cs
18
The categories of this paper are: econ
9
The categories of this paper are: nlin
19
The categories of this paper are: eess
25
The categories of this paper are: patt-sol
36
The categories of this paper are: cmp-lg
0
The categories of this paper are: hep-ph
13
The categories of this paper are: quant-ph
4
The categories of this paper are: cond-mat
21
The categories of this paper are: adap-org