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

International audienceWe 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'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