AGN number fraction in galaxy groups and clusters at z < 1.4 from the Subaru Hyper Suprime-Cam survey

Aoi Hashiguchi; Yoshiki Toba; Naomi Ota; Masamune Oguri; Nobuhiro Okabe; Yoshihiro Ueda; Masatoshi Imanishi; Satoshi Yamada; Tomotsugu Goto; Shuhei Koyama; Kianhong Lee; Ikuyuki Mitsuishi; Tohru Nagao; Atsushi J. Nishizawa; Akatoki Noboriguchi; Taira Oogi; Koki Sakuta; Malte Schramm; Mio Shibata; Yuichi Terashima; Takuji Yamashita; Anri Yanagawa; Anje Yoshimoto

arXiv · 2309.01926

AGN number fraction in galaxy groups and clusters at z < 1.4 from the Subaru Hyper Suprime-Cam survey

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Abstract

One of the key questions on active galactic nuclei (AGN) in galaxy clusters is how AGN could affect the formation and evolution of member galaxies and galaxy clusters in the history of the Universe. To address this issue, we investigate the dependence of AGN number fraction ($f_{\rm AGN}$) on cluster redshift ($z_{\rm cl}$) and distance from the cluster center ($R/R_{\rm 200}$). We focus on more than 27,000 galaxy groups and clusters at $0.1 < z_{\rm cl} < 1.4$ with more than 1 million member galaxies selected from the Subaru Hyper Suprime-Cam. By combining various AGN selection methods based on infrared (IR), radio, and X-ray data, we identify 2,688 AGN. We find that (i) $f_{\rm AGN}$ increases with $z_{\rm cl}$ and (ii) $f_{\rm AGN}$ decreases with $R/R_{\rm 200}$. The main contributors to the rapid increase of $f_{\rm AGN}$ towards high-$z$ and cluster center are IR- and radio-selected AGN, respectively. Those results indicate that the emergence of the AGN population depends on the environment and redshift, and galaxy groups and clusters at high-$z$ play an important role in AGN evolution. We also find that cluster-cluster mergers may not drive AGN activity in at least the cluster center, while we have tentative evidence that cluster-cluster mergers would enhance AGN activity in the outskirts of (particularly massive) galaxy clusters.

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Aoi Hashiguchi, Yoshiki Toba, Naomi Ota, Masamune Oguri, Nobuhiro Okabe, Yoshihiro Ueda, Masatoshi Imanishi, Satoshi Yamada, Tomotsugu Goto, Shuhei Koyama, Kianhong Lee, Ikuyuki Mitsuishi, Tohru Nagao, Atsushi J. Nishizawa, Akatoki Noboriguchi, Taira Oogi, Koki Sakuta, Malte Schramm, Mio Shibata, Yuichi Terashima, Takuji Yamashita, Anri Yanagawa, Anje Yoshimoto. 2023-09-05. AGN number fraction in galaxy groups and clusters at z < 1.4 from the Subaru Hyper Suprime-Cam survey. https://arxiv.org/abs/2309.01926

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