X-ray sources in the SSA22 Chandra field

To allow for the fullest exploration of this field, we present new optical spectroscopy from Keck/DEIMOS and Keck/LRIS, which, in combination with the literature, brings the spectroscopic completeness of the 2-8keV sample to 62%. We also make optical spectral classifications and estimate photometric redshifts for the sources without spectroscopic redshifts.

We then determine hard X-ray luminosity functions (XLFs) for the full sample of active galactic nuclei (AGNs), as well as for the broad-line AGNs (BLAGNs) and the non-BLAGNs separately. Our XLF for the full sample is in good agreement with the literature, showing relatively strong evolution over the redshift range 0.25<=z<4. The XLFs for the BLAGNs and the non-BLAGNs imply distinct evolution with redshift, with BLAGNs becoming increasingly dominant at higher redshifts and X-ray luminosities.