Accelerated galaxy growth and environmental quenching in a protocluster at z=3.24

Ke Shi, Jun Toshikawa, Kyoung Soo Lee, Tao Wang, Zheng Cai, Taotao Fang

Research output: Contribution to journalArticlepeer-review

Abstract

We present a multiwavelength study of galaxies around D4UD01, a spectroscopically confirmed protocluster at z = 3.24, to investigate environmental trends. 450 galaxies are selected based on KS band detection with photometric redshifts (photo-z) at 3.0 < z < 3.4, among which ∼12% are classified as quiescent galaxies. The quiescent galaxies are among the most massive and reddest ones in the entire sample. We identify a large photo-z galaxy overdensity in the field, which lies close to the previously spectroscopically confirmed sources of the protocluster. We find that the quiescent galaxies are largely concentrated in the overdense protocluster region with a higher quiescent fraction, showing a sign of environmental quenching. Galaxies in the protocluster are forming faster than their field counterparts as seen in the stellar mass function, suggesting early and accelerated mass assembly in the overdense regions. Although weak evidence of suppressed star formation is found in the protocluster, the statistics are not significant enough to draw a definite conclusion. Our work sheds light on how the formation of massive galaxies is affected in the dense region of a protocluster when the universe was only 2 Gyr old.

Original languageEnglish
Article number46
JournalAstrophysical Journal
Volume911
Issue number1
DOIs
Publication statusPublished - 14 Apr 2021

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

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