{
  "abstract": "Recent studies have shown that the star formation rate (SFR) correlates tightly and linearly with the mass of gravitationally bound gas, which can be delineated from the power-law tail of the column-density probability distribution function ( N -PDF) derived from dust emission observations. This relationship holds across 4 orders of magnitude within the Milky Way—spanning low-mass to high-mass star-forming regions and encompassing the extreme environment of the Central Molecular Zone. Building on this framework, we present a new approach for estimating the mass of gravitationally bound gas in molecular clouds using multiline CO isotopologue observations. Our sample includes 16 molecular clouds with robust detections in ¹² CO, ¹³ CO, and C ¹⁸ O J = 1–0, spanning both massive inner Galaxy clouds and nearby star-forming regions. We find that the N -PDFs derived from combined CO isotopologue data recover the characteristic log-normal plus power-law profiles seen in dust-based studies. The mass and spatial distribution of the self-gravitating structures estimated from both dust-based and CO-based methods agree well throughout the sample. This indicates that the CO isotopologue combination can robustly trace the self-gravitating component via the N -PDF method and provides a reliable, scalable, and velocity-resolved alternative to dust emission for identifying the star-forming gas in molecular clouds.",
  "abstract_shown": true,
  "affiliations": [
    "Chinese Academy of Sciences",
    "University of Chinese Academy of Sciences",
    "Max Planck Institute for Astronomy",
    "Nanjing University",
    "Key Laboratory of Modern Astronomy and Astrophysics",
    "Guangxi University",
    "Beijing Normal University",
    "Tsinghua University",
    "National Sun Yat-Sen University",
    "National Taiwan Normal University",
    "The University of Texas at Austin",
    "Max-Planck-Institut für Extraterrestrische Physik"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 15,
  "authors": [
    {
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        0,
        1
      ],
      "name": "Linjing Feng",
      "orcid": "0009-0003-4821-5502"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Jingwen Wu",
      "orcid": "0000-0001-7808-3756"
    },
    {
      "affs": [
        0,
        2
      ],
      "name": "Sihan Jiao",
      "orcid": "0000-0002-9151-1388"
    },
    {
      "affs": [
        3,
        4
      ],
      "name": "Zhi-Yu Zhang",
      "orcid": "0000-0002-7299-2876"
    },
    {
      "affs": [
        5
      ],
      "name": "Junzhi Wang",
      "orcid": "0000-0001-6106-1171"
    },
    {
      "affs": [
        0,
        6,
        1
      ],
      "name": "Chao-Wei Tsai",
      "orcid": "0000-0002-9390-9672"
    },
    {
      "affs": [
        7,
        0
      ],
      "name": "Di Li",
      "orcid": "0000-0003-3010-7661"
    },
    {
      "affs": [
        8,
        9
      ],
      "name": "Hauyu Baobab Liu",
      "orcid": "0000-0003-2300-2626"
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    {
      "affs": [
        0
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      "name": "Yan Sun",
      "orcid": "0000-0002-3904-1622"
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    {
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        10
      ],
      "name": "Neal J. Evans",
      "orcid": "0000-0001-5175-1777"
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    {
      "affs": [
        11
      ],
      "name": "Yuxin Lin",
      "orcid": "0000-0001-9299-5479"
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    {
      "affs": [
        0,
        1
      ],
      "name": "Hao Ruan",
      "orcid": "0009-0003-7307-6209"
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    {
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        0,
        1
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      "name": "Fangyuan Deng",
      "orcid": "0009-0003-9223-2297"
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    {
      "affs": [
        0,
        1
      ],
      "name": "Yuanzhen Xiong",
      "orcid": "0009-0000-8457-8720"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Ruofei Zhang",
      "orcid": "0009-0009-7371-1739"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9xnnsa698rp5j.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/ae9cbb",
  "fulltext_url": null,
  "id": "9xnnsa698rp5j",
  "issns": [
    "0004-637X",
    "1538-4357"
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  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/ae9cbb",
  "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": [
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      "openalex",
      "3103|Astrophysics and Star Formation Studies"
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  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/ae9cbb/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-01",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/9xnnsa698rp5j.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:11Z",
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  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Astrophysics and Star Formation Studies",
      "subfield": "stellar"
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  ],
  "title": "Trace the Self-gravitating Gas Using CO Isotopologues",
  "title_text": "Trace the Self-gravitating Gas Using CO Isotopologues",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/9xnnsa698rp5j",
  "venue": "The Astrophysical Journal",
  "versions": [
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      "doi": "10.48550/arxiv.2608.12473",
      "pid": "e39gwsbfcqatd",
      "relation": "preprint",
      "title": "Trace the Self-Gravitating Gas Using CO Isotopologues",
      "venue": "arXiv"
    }
  ]
}