The hard X-ray luminosity function of high-redshift (3 < z ≲ 5) active galactic nuclei

• DOI: 10.1093/mnras/stu2004
• Publication Date: 2014-10-31T04:26:52Z
• Authors: F. Vito; R. Gilli; C. Vignali; A. Comastri; M. Brusa; N. Cappelluti; K. Iwasawa
• Keywords: 0103 physical sciences; methods: data analysis; surveys; galaxies: active; X-rays: galaxies; Astrophysics - Astrophysics of Galaxies; 01 natural sciences; Astrophysics - Cosmology and Nongalactic Astrophysics

We present the hard-band ($2-10\,\mathrm{keV}$) X-ray luminosity function (HXLF) of $0.5-2\,\mathrm{keV}$ band selected AGN at high redshift. have assembled a sample 141 $3<z\lesssim5$ from surveys different size and depth, in order to regions $ L_X - z$ plane. The HXLF is fitted range $\mathrm{logL_X\sim43-45}$ with standard analytical evolutionary models through maximum likelihood procedure. evolution well described by pure density evolution, space declining factor $\sim10$ $z=3$ 5. A luminosity-dependent model which, normally, best represents lower redshift, also consistent data, but larger low-luminosity ($\mathrm{logL_X}<44$), high-redshift necessary constrain this model. estimated intrinsic fraction obscured column $\mathrm{logN_H}\geq23$ be $0.54\pm0.05$, no strong dependence on luminosity. This higher than value Local Universe, suggesting an luminous ($\mathrm{L_X>10^{44}\mathrm{erg\,s^{-1}}}$) $z=0$ $z>3$.