{
  "abstract": "The Central Molecular Zone (CMZ) contains most of the dense molecular gas in the Milky Way but forms stars at a surprisingly low rate. Isotopic ratios provide a unique tool to investigate both the local physical conditions and the nucleosynthetic history of this gas. I summarize recent isotopic studies toward the molecular cloud G$+$0.693$-$0.027. Deuterium fractionation (D/H ratios) reveals a cold ($T_{\\rm kin}\\lesssim30$ K), relatively quiescent gas component embedded within the otherwise warm and turbulent CMZ, indicating that the earliest stages of star formation can survive in this extreme environment. I also present new $^{12}$C/$^{13}$C measurements from HC$_3$N and HC$_5$N, including the first constraints from doubly substituted $^{13}$C isotopologues. After accounting for isotopic fractionation with astrochemical models, the inferred elemental ratio ($\\sim37$--48) exceeds the canonical CMZ assumed value ($\\sim$20), supporting a scenario in which the Galactic center is replenished by less chemically processed gas flowing inward along the Galactic bar.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.11541",
  "author_total": 1,
  "authors": [
    {
      "name": "Laura Colzi"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/epw1t8mjhex4d.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.11541",
  "fulltext_url": null,
  "id": "epw1t8mjhex4d",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.11541",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "openalex",
      "3103|Astrophysics and Star Formation Studies"
    ]
  ],
  "openalex": "W7221154057",
  "pdf_url": "https://arxiv.org/pdf/2610.11541",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-08",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/epw1t8mjhex4d.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:27:54Z",
      "native_id": "2610.11541",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.11541"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "Isotopic ratios as probes of star formation and the origin of molecular gas in the Central Molecular Zone",
  "title_text": "Isotopic ratios as probes of star formation and the origin of molecular gas in the Central Molecular Zone",
  "type": "preprint",
  "updated_at": "2026-10-30T12:27:54Z",
  "url": "https://research.draconitic.com/paper/epw1t8mjhex4d",
  "venue": "arXiv",
  "versions": []
}