Subaru High- <i>z</i> Exploration of Low-Luminosity Quasars (SHELLQs). XXV. Large-scale environments of low-luminosity quasars at <i>z</i> ∼ 6 traced by Lyα emitters
Abstract High-z quasars are believed to reside in massive dark matter haloes (DMHs), suggesting that they reside in galaxy overdense regions. However, previous observations have shown a range of environments around them. These fields have been limited to luminous quasars (M1450 ≲ −25), for which photoevaporation may hinder galaxy formation in their vicinity. Here, we present Subaru/Hyper-Suprime Cam observations of the environments of four low-luminosity quasars (−24 &lt; M1450 &lt; −22) at z ∼ 6.18, which are expected to have a smaller photoevaporation effect. We detect Lyman α emitters (LAEs) with narrowband NB872 imaging, and measure the local LAE overdensity. One quasar (J0844−0132) resides in an overdense region (δLAE = 1.97 ± 0.40), whereas the other three fields are consistent with no overdensity. These results hold over the proximity zone of each quasar, suggesting that the diverse environment around quasars is independent of photoevaporation. We find no significant correlation between the LAE overdensities and the characteristics of host galaxies and supermassive black holes. Our quasars have host stellar mass measurements from JWST, allowing us to compare them with the LAE overdensity around galaxies without quasar activity with comparable stellar masses. We find that the LAE overdensity in the J0844−0132 field is stronger than that of galaxies with similar stellar mass at z ∼ 6.
Authors
- Rikako Ishimoto (ORCID: https://orcid.org/0000-0002-2134-2902)
- Wanqiu He (ORCID: https://orcid.org/0000-0001-7759-6410)
- Shunta Shimizu
- Yoshiki Toba (ORCID: https://orcid.org/0000-0002-3531-7863)
- Yongming Liang (ORCID: https://orcid.org/0000-0002-2725-302X)
- Yoshihiro Takeda (ORCID: https://orcid.org/0000-0001-7154-3756)
- T. Yoshioka (ORCID: https://orcid.org/0000-0002-3800-0554)
- Kei Ito (ORCID: https://orcid.org/0000-0002-9453-0381)
- Junya Arita (ORCID: https://orcid.org/0009-0007-0864-7094)
- K. Iwasawa (ORCID: https://orcid.org/0000-0002-4923-3281)
- Ryo Emori
- Kentaro Koretomo
- Hiroki Hoshi
- M Imanishi
- Michael A Strauss
- Satoshi Kikuta
- Masafusa Onoue
- Nobunari Kashikawa (ORCID: https://orcid.org/0000-0003-3954-4219)
- John D Silverman (ORCID: https://orcid.org/0000-0002-0000-6977)
- Camryn L Phillips
- Yoshiki Matsuoka (ORCID: https://orcid.org/0000-0001-5063-0340)
Institutions
- Institució Catalana de Recerca i Estudis Avançats (ES)
- Institute of Astronomy and Astrophysics, Academia Sinica (TW)
- Ritsumeikan University (JP)
- Johns Hopkins University (US)
- Waseda University (JP)
- Kavli Institute for the Physics and Mathematics of the Universe (JP)
- The Graduate University for Advanced Studies, SOKENDAI (JP)
- Princeton University (US)
- DAWN Center for Independent Living (US)
- National Astronomical Observatory of Japan (JP)
- Ehime University (JP)
- University of Baltimore (US)
- Universitat de Barcelona (ES)
- The University of Tokyo (JP)
- Technical University of Denmark (DK)
Publication Details
- Journal
- Monthly Notices of the Royal Astronomical Society
- Published
- 2026-05-01
- DOI
- https://doi.org/10.1093/mnras/stag784
- Primary Topic
- Galaxies: Formation, Evolution, Phenomena
- Type
- article
- Field-Weighted Citation Impact
- 0.00