The hard X-ray luminosity function from ASCA surveys
Abstract
We summarize the nature of hard X-ray populations at ``bright'' fluxes > 10-13 ergs (2-10 keV) from optical identification of ASCA surveys, and present results of the hard X-ray luminosity function (HXLF) of Active Galactic Nuclei (AGN). Combined with HEAO1 and Chandra surveys we construct a hard-band selected sample with extremely high degree of completeness (>95 consisting of 228 AGNs over the flux range 10-11 ~ 3*E-15 ergs (2-10 keV). We find evidence that the percentage of ``type-II'' AGNs decreases with the intrinsic luminosity. The intrinsic HXLF of the whole AGNs (including type-II AGNs) is well described with the pure luminosity evolution (PLE) model up to redshift of 3. Our results directly constrain the evolution of AGNs that produce a major part of the hard X-ray background.
- Publication:
-
Astronomische Nachrichten
- Pub Date:
- 2003
- DOI:
- 10.1002/asna.200310010
- Bibcode:
- 2003AN....324...36U
- Keywords:
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- galaxies: active;
- galaxies: evolution;
- X-rays