{
  "abstract": "We present a systematic spectroscopic study of hydrogen Brackett-alpha (Br-alpha) and carbon monoxide (CO) fundamental-band (4.3-5.2 micron) emission from a homogeneous sample of 0.2-1.5 Msun pre-main-sequence (PMS) stars in the Orion Nebula observed with JWST/NIRSpec-MOS as part of our Chandra-JWST project. Using 73 Br-alpha and 46 CO spectra, we investigate correlations between warm-gas emission, stellar properties, accretion, and environment with censored correlation and regression analyses accounting for multiple testing. Br-alpha luminosity correlates strongly with accretion luminosity (Lacc), even after excluding sources within 2' of Theta1 Ori C, the nebula's main ionizing O-type star, whose radiation may bias proplyd Lacc estimates. This supports Br-alpha as a robust empirical tracer of accretion in PMS stars. Br-alpha also correlates with visual extinction (Av) and more weakly with stellar bolometric luminosity and mass. CO fundamental-band luminosities likewise correlate positively with Lacc and Av, relationships that persist in a larger combined JWST/NIRSpec+MIRI sample spanning multiple star-forming regions. In contrast to Br-alpha, CO luminosity shows no significant dependence on basic stellar properties, suggesting that warm molecular gas is governed primarily by accretion and local disk conditions. The weaker correlations of the Spitzer/IRAC spectral slope with Lacc and Av suggest that warm inner-disk gas may evolve or disperse faster than optically thick dust. Overall, the CO results tentatively indicate declining warm-gas emission as disks evolve, modulated by accretion-powered thermal and ultraviolet excitation, although variations in emitting area inherited from natal core conditions may also contribute.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.19244",
  "author_total": 20,
  "authors": [
    {
      "name": "Konstantin V. Getman"
    },
    {
      "name": "Maria Claudia Ramirez-Tannus"
    },
    {
      "name": "Jenny Frediani"
    },
    {
      "name": "Kevin L. Luhman"
    },
    {
      "name": "Eric D. Feigelson"
    },
    {
      "name": "Bayron Portilla-Revelo"
    },
    {
      "name": "Christian Rab"
    },
    {
      "name": "Valentin Brunn"
    },
    {
      "name": "Jan Forbrich"
    },
    {
      "name": "Thomas J. Haworth"
    },
    {
      "name": "Rens Waters"
    },
    {
      "name": "Arjan Bik"
    },
    {
      "name": "Charles J. Law"
    },
    {
      "name": "Andrew J. Winter"
    },
    {
      "name": "Vladimir S. Airapetian"
    },
    {
      "name": "Abygail R. Waggoner"
    },
    {
      "name": "Michael A. Kuhn"
    },
    {
      "name": "L. Ilsedore Cleeves"
    },
    {
      "name": "Sergio A. Dzib"
    },
    {
      "name": "Marco Padovani"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/fsw2bnf3nzedn.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.19244",
  "fulltext_url": null,
  "id": "fsw2bnf3nzedn",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.19244",
  "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"
    ],
    [
      "arxiv",
      "astro-ph.SR"
    ],
    [
      "openalex",
      "3103|Astrophysics and Star Formation Studies"
    ]
  ],
  "openalex": "W7222246366",
  "pdf_url": "https://arxiv.org/pdf/2610.19244",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/fsw2bnf3nzedn.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:31Z",
      "native_id": "2610.19244",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.19244"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.SR",
      "subfield": "stellar"
    }
  ],
  "title": "Tracing Accretion and Inner-Disk Gas Evolution in the Orion Nebula via Br-alpha and CO",
  "title_text": "Tracing Accretion and Inner-Disk Gas Evolution in the Orion Nebula via Br-alpha and CO",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:31Z",
  "url": "https://research.draconitic.com/paper/fsw2bnf3nzedn",
  "venue": "arXiv",
  "versions": []
}