Luminous Quasars Do Not Live in the Most Overdense Regions of Galaxies at z~4
/ Authors
H. Uchiyama, J. Toshikawa, N. Kashikawa, R. Overzier, Y. Chiang, M. Marinello, Masayuki Tanaka, Y. Niino, Shogo Ishikawa, M. Onoue
and 34 more authors
K. Ichikawa, M. Akiyama, J. Coupon, Y. Harikane, M. Imanishi, T. Kodama, Y. Komiyama, Chien-Hsiu Lee, Yen-Ting Lin, S. Miyazaki, T. Nagao, A. J. Nishizawa, Y. Ono, M. Ouchi, Shiang-Yu Wang Sokendai, Japan., Naoj, O. Nacional, Brazil, J. University, Usa, Columbia University, U. Texas, T. University, U. Geneva, Switzerland., Inst. for Nucl. Research, T. U. O. Tokyo, Graduate School of Science, Assia, Taiwan, E. University, N. University, Ipmu
/ Abstract
We present the cross-correlation between 151 luminous quasars ($M_{ \mathrm{UV}} 4 \sigma $. The distributions of the distance between quasars and the nearest protoclusters and the significance of the overdensity at the position of quasars are statistically identical to those found for $g$-dropout galaxies, suggesting that quasars tend to reside in almost the same environment as star-forming galaxies at this redshift. Using stacking analysis, we find that the average density of $g$-dropout galaxies around quasars is slightly higher than that around $g$-dropout galaxies on $1.0 - 2.5$ pMpc scales, while at $ < 0.5$ pMpc that around quasars tends to be lower. We also find that quasars with higher UV-luminosity or with more massive black holes tend to avoid the most overdense regions, and that the quasar near zone sizes are anti-correlated with overdensity. These findings are consistent with a scenario in which the luminous quasar at $z \sim4 $ resides in structures that are less massive than those expected for the progenitors of today's rich clusters of galaxies, and possibly that luminous quasars may be suppressing star formation in their close vicinity.
Journal: arXiv: Astrophysics of Galaxies
DOI: 10.1093/pasj/psx112