Eddington-limited accretion and the black hole mass function at redshift 6

Understand

We present discovery observations of a quasar in the Canada-France High-z Quasar Survey (CFHQS) at redshift z=6.44.

• We also use near-IR spectroscopy of nine CFHQS quasars at z~6 to determine black hole masses.
• These are compared with similar estimates for more luminous Sloan Digital Sky Survey (SDSS) quasars to investigate the relationship between black hole mass and quasar luminosity.
• We find a strong correlation between MgII FWHM and UV luminosity and that most quasars at this early epoch are accreting close to the Eddington limit.