Environment of SDSS quasars at $z=0.4$$-$$1.0$ explored by Subaru HSC

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Shibata, Kohei, Nagao, Tohru, Uchiyama, Hisakazu, Kubo, Mariko, Toba, Yoshiki, Omori, Kiyoaki Christopher, Kawaguchi, Toshihiro, Suzuki, Yuta
Format: Preprint
Published: 2025
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866911400319778816
author Shibata, Kohei
Nagao, Tohru
Uchiyama, Hisakazu
Kubo, Mariko
Toba, Yoshiki
Omori, Kiyoaki Christopher
Kawaguchi, Toshihiro
Suzuki, Yuta
author_facet Shibata, Kohei
Nagao, Tohru
Uchiyama, Hisakazu
Kubo, Mariko
Toba, Yoshiki
Omori, Kiyoaki Christopher
Kawaguchi, Toshihiro
Suzuki, Yuta
contents The relationship between quasars and their galaxy environment is important for understanding the evolution of galaxies and supermassive black holes, but it is not fully understood. We perform a wide and deep exploration of the environment of quasars at $0.4 < z < 1.0$ using the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey. We investigate the environment of the 1,912 spectroscopically selected quasars from the Sloan Digital Sky Survey (SDSS), using photometrically selected galaxies from the HSC-SSP data, over an area of 505 deg${^{2}}$. The quasar environment is compared to the environment of matched galaxies with similar stellar mass and redshift. We employ the $k$-nearest neighbor method to define the local galaxy number density for both the quasars and the matched galaxies at a scale of a few hundred kpc. As a result, we find that the number density of galaxies around SDSS quasars is lower than that of the matched galaxies by $\sim$11--$20\%$. We also investigate possible correlations between the local galaxy number densities and the quasar properties such as black hole mass and Eddington ratio. As a result, no correlation is found between the local galaxy number densities and these properties of quasars. These results suggest that the quasar activity is not triggered by the high number density of surrounding galaxies at the scale of a few hundred kpc.
format Preprint
id arxiv_https___arxiv_org_abs_2505_04259
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Environment of SDSS quasars at $z=0.4$$-$$1.0$ explored by Subaru HSC
Shibata, Kohei
Nagao, Tohru
Uchiyama, Hisakazu
Kubo, Mariko
Toba, Yoshiki
Omori, Kiyoaki Christopher
Kawaguchi, Toshihiro
Suzuki, Yuta
Astrophysics of Galaxies
The relationship between quasars and their galaxy environment is important for understanding the evolution of galaxies and supermassive black holes, but it is not fully understood. We perform a wide and deep exploration of the environment of quasars at $0.4 < z < 1.0$ using the Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) survey. We investigate the environment of the 1,912 spectroscopically selected quasars from the Sloan Digital Sky Survey (SDSS), using photometrically selected galaxies from the HSC-SSP data, over an area of 505 deg${^{2}}$. The quasar environment is compared to the environment of matched galaxies with similar stellar mass and redshift. We employ the $k$-nearest neighbor method to define the local galaxy number density for both the quasars and the matched galaxies at a scale of a few hundred kpc. As a result, we find that the number density of galaxies around SDSS quasars is lower than that of the matched galaxies by $\sim$11--$20\%$. We also investigate possible correlations between the local galaxy number densities and the quasar properties such as black hole mass and Eddington ratio. As a result, no correlation is found between the local galaxy number densities and these properties of quasars. These results suggest that the quasar activity is not triggered by the high number density of surrounding galaxies at the scale of a few hundred kpc.
title Environment of SDSS quasars at $z=0.4$$-$$1.0$ explored by Subaru HSC
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2505.04259