{
  "abstract": "The Andromeda galaxy (M31) exhibits a systematically low star formation efficiency (SFE) compared to other star-forming galaxies. Star formation is thought to be regulated by the mass of gravitationally bound gas. To investigate whether the low SFE in M31 originates from a scarcity of such bound gas, we analyze the dynamical state of its giant molecular cloud (GMC) population by estimating their virial parameters ($α_{\\rm vir}$). Using a JCMT-SCUBA2 850 micron dust-continuum GMC catalog as the parent sample, we combine it with IRAM 30 m CO(1-0) data to define a working sample of 173 GMCs and derive their kinematic properties. Most analyzed GMCs exhibit high $α_{\\rm vir}$, indicating that they are predominantly gravitationally unbound at the approximately 86 pc resolution of our observations. While no statistically significant global correlation is found between SFE and $α_{\\rm vir}$ for the full cloud sample, the upper quantiles of the SFE distribution show progressively stronger negative trends with increasing $α_{\\rm vir}$. This upper-tail trend may arise from the combined effects of the virial parameter limiting the upper range of SFE values accessible to the GMC population and feedback-driven disruption reducing the number of high-SFE, high-$α_{\\rm vir}$ CO-bright clouds in the observed sample. The substantial scatter in the SFE-$α_{\\rm vir}$ plane likely reflects the diverse evolutionary stages of GMCs, the temporal mismatch between gas and star formation tracers, and the limitations of a cloud-averaged virial parameter as a tracer of internal dynamical structure, making a simple one-to-one correspondence between $α_{\\rm vir}$ and instantaneous SFE difficult to recover for individual GMCs.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.18408",
  "author_total": 17,
  "authors": [
    {
      "name": "Fangyuan Deng"
    },
    {
      "name": "Sihan Jiao"
    },
    {
      "name": "Hauyu Baobab Liu"
    },
    {
      "name": "Jingwen Wu"
    },
    {
      "name": "Henrik Beuther"
    },
    {
      "name": "Fanyi Meng"
    },
    {
      "name": "Caroline Gieser"
    },
    {
      "name": "Yuxin Lin"
    },
    {
      "name": "Di Li"
    },
    {
      "name": "Chao-Wei Tsai"
    },
    {
      "name": "Junzhi Wang"
    },
    {
      "name": "Zhi-Yu Zhang"
    },
    {
      "name": "Fengwei Xu"
    },
    {
      "name": "Jakob den Brok"
    },
    {
      "name": "Linjing Feng"
    },
    {
      "name": "Zongnan Li"
    },
    {
      "name": "Yuxiang Liu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/djh67bttbcb53.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.18408",
  "fulltext_url": null,
  "id": "djh67bttbcb53",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.18408",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.18408",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-16",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/djh67bttbcb53.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:22:01Z",
      "native_id": "2609.18408",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.18408"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Low Star Formation Efficiency in M31: Evidence for a Deficit of Bound Gas",
  "title_text": "Low Star Formation Efficiency in M31: Evidence for a Deficit of Bound Gas",
  "type": "preprint",
  "updated_at": "2026-10-30T12:22:01Z",
  "url": "https://research.draconitic.com/paper/djh67bttbcb53",
  "venue": "arXiv",
  "versions": []
}