{
  "abstract": "Massive quiescent galaxies (QGs) at high redshifts are likely progenitors of massive elliptical galaxies in the local Universe. Recent discoveries of high-redshift QGs in overdensities (galaxy groups and protoclusters) have highlighted the relationship between massive galaxy quenching and their surrounding environment. We spectroscopically confirm a galaxy group associated with a massive QG at z spec = 4.53 from the Lyman break feature using Subaru/FOCAS. This group consists of at least three star-forming galaxies within 150 pkpc of the QG, suggesting a physical association necessary for galaxy quenching. To investigate the role of the surrounding environment, we also perform a statistical analysis to characterize the typical environment of QGs at high redshifts. By selecting QGs using a star formation rate-based selection in the COSMOS field, we find that the quiescent fraction is higher in overdensities than in the field at 1 < z < 5. In particular, the elevated quiescent fraction within small-scale overdensities (∼200 pkpc) demonstrates that environmental quenching, possibly driven by galaxy mergers and interactions, plays a major role in the evolution of massive QGs at high redshifts. By extending the low-redshift mass and environmental quenching model up to z ∼ 5, we confirm similar trends to those inferred from the Sloan Digital Sky Survey red galaxy fraction at z < 1. While environmental dependence weakens at z ≳ 3 for the overall population, a clear correlation persists specifically for more massive galaxies. This mass-dependent environmental effect suggests a downsizing trend, highlighting that the accelerated evolution of massive galaxies in high-density regions is already in place in the early Universe.",
  "abstract_shown": true,
  "affiliations": [
    "The Graduate University for Advanced Studies",
    "National Astronomical Observatory of Japan",
    "The University of Tokyo",
    "Cosmic Dawn Center (DAWN)",
    "Technical University of Denmark",
    "Faculty of Science and Engineering, Waseda University",
    "Waseda University",
    "National Institutes of Natural Sciences (NINS)",
    "National Taiwan University",
    "Physics Division",
    "Kwansei Gakuin University",
    "Tohoku University",
    "University of Copenhagen"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 13,
  "authors": [
    {
      "affs": [
        0,
        1
      ],
      "name": "Takumi Kakimoto",
      "orcid": "0000-0003-2918-9890"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Masayuki Tanaka",
      "orcid": "0000-0002-5011-5178"
    },
    {
      "affs": [
        1,
        2
      ],
      "name": "Makoto Ando",
      "orcid": "0000-0002-4225-4477"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Kei Ito",
      "orcid": "0000-0002-9453-0381"
    },
    {
      "affs": [
        5,
        6
      ],
      "name": "Ken Mawatari",
      "orcid": "0000-0003-4985-0201"
    },
    {
      "affs": [
        0,
        7
      ],
      "name": "Masato Onodera",
      "orcid": "0000-0003-3228-7264"
    },
    {
      "affs": [
        6
      ],
      "name": "Rhythm Shimakawa",
      "orcid": "0000-0003-4442-2750"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Francesco Valentino",
      "orcid": "0000-0001-6477-4011"
    },
    {
      "affs": [
        8,
        9
      ],
      "name": "Po-Feng Wu",
      "orcid": "0000-0002-9665-0440"
    },
    {
      "affs": [
        0,
        7
      ],
      "name": "Kiyoto Yabe",
      "orcid": "0000-0001-6229-4858"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Shuowen Jin",
      "orcid": "0000-0002-8412-7951"
    },
    {
      "affs": [
        10,
        11
      ],
      "name": "Mariko Kubo",
      "orcid": "0000-0002-7598-5292"
    },
    {
      "affs": [
        3,
        12
      ],
      "name": "Sune Toft",
      "orcid": "0000-0003-3631-7176"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/48f9tpyt4zwv2.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/aeaadf",
  "fulltext_url": null,
  "id": "48f9tpyt4zwv2",
  "issns": [
    "1538-4357",
    "0004-637X"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeaadf",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "feed-journal",
      "astronomy/general"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/aeaadf/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-04",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/48f9tpyt4zwv2.ris",
  "sources": [
    {
      "first_seen": "2026-11-04T12:20:44Z",
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "journal-openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "The Role of Small-scale Environments in the Quenching of Massive Galaxies at 1 < z < 5",
  "title_text": "The Role of Small-scale Environments in the Quenching of Massive Galaxies at 1 < z < 5",
  "type": "peer-reviewed",
  "updated_at": "2026-11-06T00:21:00Z",
  "url": "https://research.draconitic.com/paper/48f9tpyt4zwv2",
  "venue": "The Astrophysical Journal",
  "versions": []
}