AGN evolution revealed from X-ray surveys

作者：Ueda Y^*

来源：Symposium on the X-ray Universe 2005, 2005-09-26 to 2005-09-30.

• X-rays
• AGN
• surveys
• X-ray background

I review the cosmological evolution of Active Galactic Nuclei (AGNs) revealed from X-ray surveys, mainly based on studies by using hard (> 2 keV) X-ray selected samples. The hard X-ray luminosity function of type-1 and type-2 AGNs is well described by the luminosity dependent density evolution, where the cut-off redshift of density evolution increases with luminosity. This suggest anti-hierarchical (or down-sizing) growth of supermassive black holes in galactic centers. The black hole mass function at z < 1 can be explained, on average, as the consequence of "standard" accretion with a radiative efficiency of approximate to 0.1. Population synthesis models constructed from the observational results of hard X-ray luminosity function and absorption function of AGNs are now close to finalization. However, toward complete understanding of the X-ray background origin, there still remains several issues to be solved by current and future missions.

• 出版日期2006