{
  "abstract": "The classical radiation-pressure instability predicts thermal variability in luminous black-hole accretion disks, whereas most disk-dominated X-ray binary soft states remain comparatively stable. We examine the local thermal stability of a thin disk in which net vertical magnetic flux contributes to the radial stress. We separate the equilibrium enhancement of the radial stress from its response during a thermal perturbation. The direct local criterion is written in terms of the logarithmic heating slope, q ₊ < q +,crit , and therefore does not require a decomposition of the turbulent stress. For the illustrative closure δ = ζ β z β φ / α , η δ = − d ln δ / d ln H describes the response of the fractional correction δ , whereas the additional stress itself responds through Γ nf = d ln W nf / d ln H . For a representative 10 M ⊙ disk at R = 20 r g and M ̇ = 0.5 M ̇ Edd , adopting fixed local mass flux on the thermal timescale, ( γ , γ p ) = (1, 0), and d ln ζ / d ln H = 0 gives β z crit = 0.0176 for ζ = 1 and 0.1338 for ζ = 0.25. These values are conditional on the adopted stress closure and field-response prescription rather than universal magnetic thresholds. Fixed- B z equilibrium sequences, constructed with a separate equilibrium relation for B φ ( H ), show that the unstable interval narrows but remains finite for both H / R < 0.1 and H / R < 0.2.",
  "abstract_shown": true,
  "affiliations": [
    "Western University",
    "Ferdowsi University of Mashhad",
    "Tata Institute of Fundamental Research"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 3,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Shahram Abbassi",
      "orcid": "0000-0003-0428-2140"
    },
    {
      "affs": [
        1
      ],
      "name": "Armin Memarian"
    },
    {
      "affs": [
        2
      ],
      "name": "Samik Mitra",
      "orcid": "0000-0002-5730-0376"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/dtvaxpv0g4t9a.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-4357/ae9ec2",
  "fulltext_url": null,
  "id": "dtvaxpv0g4t9a",
  "issns": [
    "1538-4357",
    "0004-637X"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-4357/ae9ec2",
  "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": [
    [
      "feed-journal",
      "astronomy/general"
    ],
    [
      "openalex",
      "3103|Astrophysical Phenomena and Observations"
    ]
  ],
  "openalex": "W7203966839",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-4357/ae9ec2/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-27",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/dtvaxpv0g4t9a.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:17:17Z",
      "native_id": "10.3847/1538-4357/ae9ec2",
      "source": "feed-iop",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/ae9ec2"
    },
    {
      "first_seen": "2026-10-30T12:18:11Z",
      "native_id": "10.3847/1538-4357/ae9ec2",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-4357/ae9ec2"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "journal-openalex:3103|Stellar, planetary, and galactic studies",
      "subfield": "stellar"
    }
  ],
  "title": "Thermal Stability of Radiation-pressure-dominated Accretion Disks Threaded by Net Vertical Magnetic Flux",
  "title_text": "Thermal Stability of Radiation-pressure-dominated Accretion Disks Threaded by Net Vertical Magnetic Flux",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:11Z",
  "url": "https://research.draconitic.com/paper/dtvaxpv0g4t9a",
  "venue": "The Astrophysical Journal",
  "versions": []
}