A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). VI. Distant Filamentary Structures Pointed Out by High- z Radio Galaxies at z ∼4

Hisakazu Uchiyama, Takuji Yamashita, Jun Toshikawa, Nobunari Kashikawa, Kohei Ichikawa, Mariko Kubo, Kei Ito, Nozomu Kawakatu, Tohru Nagao, Yoshiki Toba, Yoshiaki Ono, Yuichi Harikane, Masatoshi Imanishi, Masaru Kajisawa, Chien Hsiu Lee, Yongming Liang

Research output: Contribution to journalArticlepeer-review

Abstract

We present the environmental properties around high-z radio galaxies (HzRGs) at z ∼4, which have been poorly investigated because of their rarity. We use the largest samples of HzRGs and g-dropout galaxy overdense regions at z ∼4, which were constructed from the Hyper Suprime-Cam Subaru Strategic Program, to characterize the HzRG environments statistically. We measure the g-dropout galaxy overdensities around 21 HzRGs whose rest-frame 1.4 GHz radio luminosities (L 1.4 GHz) are 1026-27 W Hz-1. We find that the overdensities around the faint HzRGs with L 1.4 GHz ∼1026.0-26.5 W Hz-1 tend to be higher than those of the g-dropout galaxies. On the other hand, no significant difference of density environments is found between the luminous HzRGs with L 1.4 GHz ∼1026.5-27.0 W Hz-1 and the g-dropout galaxies. The HzRGs are found to occupy more massive halos than g-dropout galaxies through a cross-correlation between the HzRGs and g-dropout galaxies. This trend is more pronounced in the faint HzRGs. These results are consistent with a scenario where HzRGs get older and more massive as the radio luminosity decreases. The HzRGs are expected to trace the progenitors of Local Cluster halos from their calculated halo mass. In addition, we find that surrounding galaxies tend to distribute along the radio jet major axis of the HzRGs at angular distances of ≲500 physical kpc. Our findings imply the onset of the filamentary structures around the HzRGs at z ∼4.

Original languageEnglish
Article number76
JournalAstrophysical Journal
Volume926
Issue number1
DOIs
Publication statusPublished - 15 Feb 2022

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Fingerprint

Dive into the research topics of 'A Wide and Deep Exploration of Radio Galaxies with Subaru HSC (WERGS). VI. Distant Filamentary Structures Pointed Out by High- z Radio Galaxies at z ∼4'. Together they form a unique fingerprint.

Cite this