{
  "abstract": "We report on JWST/MIRI low-resolution spectroscopy ($5$-$12 μ$m) and imaging ($15$-$25 μ$m) of the black hole X-ray binary XTE~J1118+480 in quiescence, at an X-ray luminosity nine orders of magnitude sub-Eddington, together with contemporaneous optical monitoring and a radio upper limit of $4.5~μ$Jy at 6 GHz. With the donor subtracted, the $5$-$12 μ$m continuum is curved, turning over near $6~μ$m; a single power law is rejected in favor of a $764\\pm 9$ K blackbody. Longward of the turnover the spectral index is $α= +1.21\\pm0.36$, steeper at the $2σ$ level than the flat to slightly inverted spectrum of a compact jet. Interpreted as synchrotron, the turnover implies equipartition fields of $\\sim$$10^{4}$ G on scales of tens of gravitational radii, but the MIRI photometry at $15$-$21~μ$m-taken $2.6$ hr before the spectrum-lies $30$-$90$ per cent above its extrapolation, suggesting a second self-absorbed zone. A single partially self-absorbed jet spectrum can reach the photometry only at the expense of the spectral curvature and the $25.5~μ$m upper limit, so a steady compact jet is disfavored, although not excluded. Representative self-consistent irradiated-disk models instead reproduce the principal features of the $5$-$25~μ$m spectral energy distribution, with a directly illuminated dust wall at $\\simeq 5$ binary separations, outside the tidal-truncation radius, and a minimum dust mass of order $10^{22}$ g. This is the first spectroscopic evidence, though not yet conclusive, favoring circumbinary dust over a jet in a quiescent black hole X-ray binary.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.36318",
  "author_total": 12,
  "authors": [
    {
      "name": "Zihao Zuo"
    },
    {
      "name": "Elena Gallo"
    },
    {
      "name": "Nuria Calvet"
    },
    {
      "name": "Richard M. Plotkin"
    },
    {
      "name": "David M. Russell"
    },
    {
      "name": "Gabriele Cugno"
    },
    {
      "name": "Rob Fender"
    },
    {
      "name": "Fraser Lewis"
    },
    {
      "name": "Joseph Michail"
    },
    {
      "name": "Jon M. Miller"
    },
    {
      "name": "James C. A. Miller-Jones"
    },
    {
      "name": "Fan Zou"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/bg2wgz782w4jk.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.36318",
  "fulltext_url": null,
  "id": "bg2wgz782w4jk",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.36318",
  "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.HE"
    ],
    [
      "openalex",
      "3103|Astrophysical Phenomena and Observations"
    ]
  ],
  "openalex": "W7214942315",
  "pdf_url": "https://arxiv.org/pdf/2609.36318",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-28",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/bg2wgz782w4jk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.36318",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.36318"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "JWST/MIRI Spectroscopy of the Quiescent Black Hole X-ray Binary XTE J1118+480: Constraints on Jet and Circumbinary Dust Contributions to the Mid-infrared Emission",
  "title_text": "JWST/MIRI Spectroscopy of the Quiescent Black Hole X-ray Binary XTE J1118+480: Constraints on Jet and Circumbinary Dust Contributions to the Mid-infrared Emission",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/bg2wgz782w4jk",
  "venue": "arXiv",
  "versions": []
}