First Results from the Canada-France High-z Quasar Survey: Constraints on the z = 6 Quasar Luminosity Function and the Quasar Contribution to Reionization

Chris J. Willott , Xavier Delfosse (1) , Thierry Forveille (1) , Philippe Delorme (1) , Stephen D. J. Gwyn

1 LAOG - Laboratoire d'Astrophysique de Grenoble

We present preliminary results of a new quasar survey being undertaken with multicolor optical imaging from the Canada-France-Hawaii Telescope. The current data consist of 3.83 deg2 of imaging in the i' and z' filters to a 10 σ limit of z'<23.35. Near-infrared photometry of 24 candidate 5.7-3.2 at 95% confidence. We find that the comoving space density of quasars brighter than M1450=-23.5 declines by a factor of >25 from z=2 to 6, mirroring the decline observed for high-luminosity quasars. We consider the contribution of the quasar population to the ionizing photon density at z=6 and the implications for reionization. We show that the current constraints on the quasar population give an ionizing photon density <

Chris J. Willott, Xavier Delfosse, Thierry Forveille, Philippe Delorme, Stephen D. J. Gwyn. First Results from the Canada-France High-z Quasar Survey: Constraints on the z = 6 Quasar Luminosity Function and the Quasar Contribution to Reionization. The Astrophysical Journal, 2005, 633, pp.630-637. ⟨10.1086/462408⟩. ⟨hal-00398196⟩