{
  "abstract": "Over the last 40 years, low-temperature reaction rate coefficients in astrochemical databases have largely come from CRESU ( Cinétique de Réaction en Ecoulement Supersonique Uniforme ) experiments, where the flow is described by a single temperature under an assumption of local thermal equilibrium. Here we directly test this assumption using infrared frequency comb spectroscopy, laser-induced fluorescence, Pitot measurements, and computational fluid dynamics in seeded supersonic flows. We observe persistent vibrational excitation in carbonyl sulfide (OCS) and nitrous oxide (N ₂ O) under all conditions examined, despite efficient rotational cooling, demonstrating a breakdown of local thermal equilibrium within the flow. In parallel, we find that conventional Pitot-derived temperatures do not consistently reflect the energetic state of the reacting ensemble. These results show that the reacting ensemble in CRESU flows cannot always be described by a single thermodynamic temperature, particularly for species with low-lying vibrational modes, and that internal-state distributions should be carefully considered when interpreting low-temperature reaction rate coefficients in astrochemical kinetic databases.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": null,
  "author_total": 8,
  "authors": [
    {
      "name": "Lok Yiu Wu",
      "orcid": "0009-0006-0620-1139"
    },
    {
      "name": "Luke Driver"
    },
    {
      "name": "Daniel I. Lucas",
      "orcid": "0000-0002-1841-2076"
    },
    {
      "name": "Madeleine E. Robertson"
    },
    {
      "name": "Nikil Kapur",
      "orcid": "0000-0003-1041-8390"
    },
    {
      "name": "Dwayne E. Heard",
      "orcid": "0000-0002-0357-6238"
    },
    {
      "name": "Gregory N. de Boer",
      "orcid": "0000-0002-5647-1771"
    },
    {
      "name": "Julia H. Lehman",
      "orcid": "0000-0001-6610-6519"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/394dq89zr7vaq.bib",
  "cited_by": 0,
  "doi": "10.1038/s42004-026-02244-8",
  "fulltext_url": null,
  "id": "394dq89zr7vaq",
  "issns": [
    "2399-3669"
  ],
  "landing_url": "https://www.nature.com/articles/s42004-026-02244-8",
  "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": [
    [
      "openalex",
      "1607|Spectroscopy and Laser Applications"
    ]
  ],
  "openalex": "W7213374755",
  "pdf_url": "https://www.nature.com/articles/s42004-026-02244-8_reference.pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-13",
  "publisher": "Springer Science and Business Media LLC",
  "ris": "https://research.draconitic.com/paper/394dq89zr7vaq.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:51Z",
      "native_id": "10.1038/s42004-026-02244-8",
      "source": "crossref",
      "url": "https://www.nature.com/articles/s42004-026-02244-8"
    }
  ],
  "subjects": [
    {
      "field": "chemistry",
      "origin": "openalex:1607|Spectroscopy and Laser Applications",
      "subfield": "physical"
    }
  ],
  "title": "Non-thermal effects and temperature disparities in uniform supersonic flows",
  "title_text": "Non-thermal effects and temperature disparities in uniform supersonic flows",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:17:51Z",
  "url": "https://research.draconitic.com/paper/394dq89zr7vaq",
  "venue": "Communications Chemistry",
  "versions": []
}