The high-redshift (z>3) AGN population in the 4 Ms Chandra Deep Field South

Дата и время публикации : 2012-09-19T09:31:49Z

Авторы публикации и институты :
F. Vito (Dipartimento di Astronomia, Universitá di Bologna, Italy, INAF-OABo, Italy)
C. Vignali (Dipartimento di Astronomia, Universitá di Bologna, Italy, INAF-OABo, Italy)
R. Gilli (INAF-OABo, Italy)
A. Comastri (INAF-OABo, Italy)
K. Iwasawa (ICREA and ICC, Universitat de Barcelona, Spain)
W. N. Brandt (Department of Astronomy and Astrophysics, The Pennsylvania State University, USA, Institute for Gravitation and the Cosmos, The Pennsylvania State University, USA)
D. M. Alexander (Department of Physics, University of Durham, UK)
M. Brusa (Max Planck Institut für Extraterrestische Physik, Garching, Germany)
B. Lehmer (The Johns Hopkins University, Baltimore, USA, NASA Goddard Space Flight Centre, Greenbelt, USA)
F. E. Bauer (Pontificia Universidad Católica de Chile, Santiago, Chile, Space Science Institute, Boulder, USA)
D. P. Schneider (Department of Astronomy and Astrophysics, The Pennsylvania State University, USA, Institute for Gravitation and the Cosmos, The Pennsylvania State University, USA)
Y. Q. Xue (Department of Astronomy, University of Science and Technology of China, China)
B. Luo (Department of Astronomy and Astrophysics, The Pennsylvania State University, USA, Institute for Gravitation and the Cosmos, The Pennsylvania State University, USA)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: 18 pages, 44 figures, a few references added, a few changes made to match the printed version
Первичная категория: astro-ph.CO

Все категории : astro-ph.CO, astro-ph.HE

Краткий обзор статьи: We present results from a spectral analysis of a sample of high-redshift (z>3) X-ray selected AGN in the 4 Ms Chandra Deep Field South (CDF-S), the deepest X-ray survey to date. The sample is selected using the most recent spectroscopic and photometric information available in this field. It consists of 34 sources with median redshift z=3.7, 80 median net counts in the 0.5-7 keV band and median rest-frame absorption-corrected luminosity $L_{2-10 rmn{keV}}approx1.5times10^{44}rmn{erg} rmn{s^{-1}}$. Spectral analysis for the full sample is presented and the intrinsic column density distribution, corrected for observational biases using spectral simulations, is compared with the expectations of X-ray background (XRB) synthesis models. We find that $approx57$ per cent of the sources are highly obscured ($N_H>10^{23}rmn{cm^{-2}}$). Source number counts in the $0.5-2rmn{keV}$ band down to flux $F_{0.5-2 rmn{keV}}approx4times10^{-17}rmn{erg} rmn{s^{-1}cm^{-2}}$ are also presented. Our results are consistent with a decline of the AGN space density at z>3 and suggest that, at those redshifts, the AGN obscured fraction is in agreement with the expectations of XRB synthesis models.

Category: Physics