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arXiv · 2004.07604

The XMM deep survey in the CDFS XI. X-ray properties of 185 bright sources

K. Iwasawa·A. Comastri·C. Vignali·R. Gilli·G. Lanzuisi·W . N. Brandt·P. Tozzi·M. Brusa·F. J. Carrera·P. Ranalli·V. Mainieri·I. Georgantopoulos·S. Puccetti·M. Paolillo
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Abstract

We present X-ray spectra of 185 bright sources detected in the XMM-Newton deep survey of the Chandra Deep Field South, combining the three EPIC cameras. The 2-10 keV flux limit of the sample is 2e-15 erg/s/cm2. The sources are distributed over a redshift range of z=0.1-3.8. Eleven new X-ray redshift measurements are included. A spectral analysis was performed using a simple model to obtain absorbing column densities, rest-frame 2-10 keV luminosities and Fe K line properties of 180 sources at z>0.4. Obscured AGN are found to be more abundant toward higher redshifts. Using the XMM-Newton data alone, seven Compton-thick AGN candidates are identified, which makes the Compton-thick AGN fraction to be ~4%. An exploratory spectral inspection method with two rest-frame X-ray colours and an Fe line strength indicator is introduced and tested against the results from spectral fitting. This method works reasonably well to characterise a spectral shape and can be useful for a pre-selection of Compton-thick AGN candidates. We found six objects exhibiting broad Fe K lines out of 21 unobscured AGN of best data quality, implying a detection rate of ~30%. Five redshift spikes, each of which has more than six sources, are identified in the redshift distribution of the X-ray sources. Contrary to the overall trend, the sources at the two higher-redshift spikes at z=1.61 and z=2.57 have puzzlingly low obscuration.

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K. Iwasawa, A. Comastri, C. Vignali, R. Gilli, G. Lanzuisi, W . N. Brandt, P. Tozzi, M. Brusa, F. J. Carrera, P. Ranalli, V. Mainieri, I. Georgantopoulos, S. Puccetti, M. Paolillo. 2020-04-16. The XMM deep survey in the CDFS XI. X-ray properties of 185 bright sources. https://doi.org/10.1051/0004-6361/201937246

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