Clustering of quasars in a wide luminosity range at redshift 4 with Subaru Hyper Suprime-Cam Wide-field imaging

摘要

We examine the clustering of quasars over a wide luminosity range, by utilizing 901 quasars at |$overline{z}_{m phot}sim 3.8$| with ?24.73??M1450???22.23 photometrically selected from the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) S16A Wide2 date release and 342 more luminous quasars at 3.4??zspec??4.6 with ?28.0??M1450???23.95 from the Sloan Digital Sky Survey that fall in the HSC survey fields. We measure the bias factors of two quasar samples by evaluating the cross-correlation functions (CCFs) between the quasar samples and 25790 bright z?～?4 Lyman break galaxies in M1450???21.25 photometrically selected from the HSC dataset. Over an angular scale of 10|${^{primeprime}_{.}}$|0 to 1000|${^{primeprime}_{.}}$|0, the bias factors are |$5.93^{+1.34}_{-1.43}$| and |$2.73^{+2.44}_{-2.55}$| for the low- and high-luminosity quasars, respectively, indicating no significant luminosity dependence of quasar clustering at z?～?4. It is noted that the bias factor of the luminous quasars estimated by the CCF is smaller than that estimated by the auto-correlation function over a similar redshift range, especially on scales below 40|${^{primeprime}_{.}}$|0. Moreover, the bias factor of the less-luminous quasars implies the minimal mass of their host dark matter halos is 0.3–2?×?1012?h?1?M⊙, corresponding to a quasar duty cycle of 0.001–0.06.