Astronomy and Astrophysics – Astronomy
Scientific paper
Jan 2012
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2012aas...21932101m&link_type=abstract
American Astronomical Society, AAS Meeting #219, #321.01
Astronomy and Astrophysics
Astronomy
Scientific paper
We investigate the high-redshift quasar luminosity function down to I 25 in the Cosmic Evolution Survey (COSMOS) field, using a selection that we demonstrate to be close to 100% complete for Type-1 quasars at the redshifts of interest. Careful analysis of the extensive COSMOS photometry and imaging data allows us to remove stellar and low-redshift contaminants from our candidate list. We find 133 likely quasars at z>3.1, 39 of which have prior spectroscopic confirmation. These confirmed and likely quasars are used to compute the rest-frame UV QLF in the redshift bins 3.1 < z < 3.5 and 3.5 < z < 5. We find strong evolution of the faint end of the QLF between these redshifts, with the space density of faint quasars decreasing by roughly a factor of four from z 3.2 to z 4. This demonstrates that the population of faint quasars is decreasing rapidly with redshift above z 3, in accord with what has been found for more luminous optical and X-ray quasars. We compare the rest-frame UV luminosity functions found here with the X-ray luminosity function at z > 3, and find that they evolve similarly between z 4 and z 3.2; however, the different normalizations imply that roughly 75% of X-ray bright active galactic nuclei (AGN) at z 3-4 are optically obscured. The implications of these results for the contribution of quasars to reionization are discussed.
Capak Peter
Civano Francesca
Elvis Martin
Masters Daniel
Mobasher Bahram
No associations
LandOfFree
A New Determination Of The High-redshift Quasar Luminosity Function To I 25 In The COSMOS Field does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with A New Determination Of The High-redshift Quasar Luminosity Function To I 25 In The COSMOS Field, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and A New Determination Of The High-redshift Quasar Luminosity Function To I 25 In The COSMOS Field will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1579975