{
  "abstract": "We performed a spectral analysis of long-term observations (2016-2019) of the black hole binary Cygnus X-1 using AstroSat, covering its hard, intermediate, and soft states. During soft states, we found that a typical spectrum fitted with a single Comptonization, a thermal disc, and an iron line yields poor fits and unphysically small disk radii (R_in < 1 R_g). While adding a relativistic disk component (kerrbb) improved the fit but required high color factors (f_col ~ 3.35-5.08), indicating additional Comptonization. We therefore adopted a dual-Comptonization model with hot (optically thin) and warm (optically thick) coronae. This provided consistent good fits across all soft and hard states of Cygnus X-1. The spectral evolution reveals the critical role of dual Comptonization in shaping the broadband emission of Cygnus X-1.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.12072",
  "author_total": 5,
  "authors": [
    {
      "name": "H Lalthantluanga"
    },
    {
      "name": "Akash Garg"
    },
    {
      "name": "Ranjeev Misra"
    },
    {
      "name": "Vanzarmawii Chhangte"
    },
    {
      "name": "Lalthakimi Zadeng"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/e7g0he11hn9rw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.12072",
  "fulltext_url": null,
  "id": "e7g0he11hn9rw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.12072",
  "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": null,
  "pdf_url": "https://arxiv.org/pdf/2609.12072",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-10",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/e7g0he11hn9rw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:07Z",
      "native_id": "2609.12072",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.12072"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Long-term X-ray spectral analysis of Cygnus X-1 using AstroSat",
  "title_text": "Long-term X-ray spectral analysis of Cygnus X-1 using AstroSat",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:07Z",
  "url": "https://research.draconitic.com/paper/e7g0he11hn9rw",
  "venue": "arXiv",
  "versions": []
}