{
  "abstract": "Observing the earliest stages of high-mass star formation in the mid-infrared (mid-IR) is challenging because the extinction is high and the resolution limited. Millimeter vibrationally and torsionally excited transitions of several molecules have been proposed as indirect probes of local mid-IR radiation fields around young stellar objects (YSOs). We investigate the excitation and spatial distribution of torsionally excited methanol ($\\mathrm{CH_3OH}$) in 12 high-mass star-forming clumps in different evolutionary stages, assessing their potential as tracers of the mid-IR luminosity of embedded protostars. We analyzed rotational transitions of methanol within the same torsionally excited states $v_\\mathrm{t}$$\\geq$1 in the Atacama Large Millimeter/submillimeter Array (ALMA) 890 $\\mathrm{μm}$ observations and compared them with Spitzer 24 $\\mathrm{μm}$ data by plotting line luminosities normalized by methanol abundance against mid-IR luminosities. The torsionally excited methanol emission is generally compact and systematically coincident with ALMA dust continuum peaks and 24 $\\mathrm{μm}$ emission, even in faint sources. The only clump without an IR counterpart also shows no $v_\\mathrm{t}$$\\geq$1 emission, supporting radiative pumping as the dominant excitation mechanism. We found a promising power-law trend between $v_\\mathrm{t}$$\\geq$1 methanol lines and 24 $\\mathrm{μm}$ luminosities, largely independent of the methanol abundance. $\\mathrm{CH_3OH}$ $v_\\mathrm{t}$$\\geq$1 transitions appear to be promising tracers of local mid-IR radiation fields of embedded protostars, providing core-scale information even in highly extincted regions. As a pilot study, our results suggest that extending our study to a larger statistical sample is crucial for testing and improving this method.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.37955",
  "author_total": 12,
  "authors": [
    {
      "name": "C. Sanna"
    },
    {
      "name": "S. Leurini"
    },
    {
      "name": "A. Giannetti"
    },
    {
      "name": "E. Schisano"
    },
    {
      "name": "L. Testi"
    },
    {
      "name": "S. Molinari"
    },
    {
      "name": "J. S. Urquhart"
    },
    {
      "name": "T. Pillai"
    },
    {
      "name": "F. Massi"
    },
    {
      "name": "K. Immer"
    },
    {
      "name": "E. Molinari"
    },
    {
      "name": "S. Casu"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/78f9dbggthfy9.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.37955",
  "fulltext_url": null,
  "id": "78f9dbggthfy9",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.37955",
  "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"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2609.37955",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-29",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/78f9dbggthfy9.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.37955",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.37955"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Torsionally excited methanol in massive young stellar objects: The role of the mid-IR radiation field",
  "title_text": "Torsionally excited methanol in massive young stellar objects: The role of the mid-IR radiation field",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/78f9dbggthfy9",
  "venue": "arXiv",
  "versions": []
}