Black hole mass and Eddington ratio distributions of less-luminous quasars at $z\sim4$ in the Subaru Hyper Suprime-Cam Wide field

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We investigate the black hole mass function (BHMF) and Eddington ratio distribution function (ERDF) of broad-line AGNs at z=4, based on a sample of 52 quasars with i<23.2 at 3.50 < z < 4.25 from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) S16A-Wide2 dataset, and 1,462 quasars with i<20.2 in the same redshift range from the Sloan Digital Sky Survey (SDSS) DR7 quasar catalog.

• Virial BH masses of quasars are estimated using the width of the CIV 1549{\AA} line and the continuum luminosity at 1350{\AA}.
• To obtain the intrinsic broad-line AGN BHMF and ERDF, we correct for the incompleteness in the low-mass and/or low-Eddington-ratio ranges caused by the flux-limited selection.
• The resulting BHMF is constrained down to $\log M_{\rm BH}/M_{\odot}\sim7.5$.