2023/07/05 by Junya Arita, Arita, Junya, Nobunari Kashikawa +23 · 1 citation
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics of Galaxies (astro-ph.GA) #Dark Matter and Cosmic Phenomena #FOS: Physical sciences #Scientific Research and Discoveries
paper · pdf · doi:10.48550/arxiv.2307.02531
openalex publication_date 2023/07/05 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/01
We present, for the first time, dark matter halo (DMH) mass measurement of quasars at z∼6 based on a clustering analysis of 107 quasars. Spectroscopically identified quasars are homogeneously extracted from the HSC-SSP wide layer over 891 deg2. We evaluate the clustering strength by three different auto-correlation functions: projected correlation function, angular correlation function, and redshift-space correlation function. The DMH mass of quasars at z∼6 is evaluated as 5.0-4.0+7.4×1012 h-1M_\odot with the bias parameter b=20.8±8.7 by the projected correlation function. The other two estimators agree with these values, though each uncertainty is large. The DMH mass of quasars is found to be nearly constant ∼1012.5 h-1M_\odot throughout cosmic time, suggesting that there is a characteristic DMH mass where quasars are always activated. As a result, quasars appear in the most massive halos at z ∼ 6, but in less extreme halos thereafter. The DMH mass does not appear to exceed the upper limit of 1013 h-1M_\odot, which suggests that most quasars reside in DMHs with Mhalo<1013 h-1M_\odot across most of the cosmic time. Our results supporting a significant increasing bias with redshift are consistent with the bias evolution model with inefficient AGN feedback at z∼6. The duty cycle (fduty) is estimated as 0.019±0.008 by assuming that DMHs in some mass interval can host a quasar. The average stellar mass is evaluated from stellar-to-halo mass ratio as M_*=6.5-5.2+9.6×1010 h-1M_\odot, which is found to be consistent with [C II] observational results.