{
  "abstract": "We present a systematic spectral study of the X-ray emission from the Narrow- Line Seyfert 1 (NLS1) galaxy Ark 564 using Swift/XRT observations spanning sixteen years. The source exhibits significant variability in both the soft and hard X-ray bands, along with a strong positive correlation between them, indicating a closely coupled emission mechanism within the accretion flow-corona system. A simple absorbed power-law model is statistically insufficient to describe the spectra, confirming the presence of an additional soft component. To investigate the origin of the soft excess, we performed multi-model spectral fitting. Incor- porating a warm Comptonization component yields a statistically improved fit, supporting the scenario in which the soft excess arises from Comptonization in a warm, optically thick corona. We also applied a relativistic reflection model to representative observations; however, given the moderate spectral resolution and limited high-energy coverage of Swift/XRT, the current data do not allow us to robustly determine whether reflection provides a superior or physically preferred description. Our results indicate that warm Comptonization offers a consistent explanation for the observed soft excess in Ark 564 within the limitations of the available data, while deeper broadband observations are required to defini- tively distinguish between competing models and comprehensively characterise the long-term X-ray spectral variability of the source",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": "Journal reference: Astrophysics & Space Science,2026",
  "arxiv": "2609.30793",
  "author_total": 7,
  "authors": [
    {
      "name": "Neha P R"
    },
    {
      "name": "Nikita S Arun"
    },
    {
      "name": "Savithri H. Ezhikode"
    },
    {
      "name": "Ranjeev Misra"
    },
    {
      "name": "Bari Maqbool"
    },
    {
      "name": "Jeena K"
    },
    {
      "name": "Joe Jacob"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/awxh22qsakng8.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.30793",
  "fulltext_url": null,
  "id": "awxh22qsakng8",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.30793",
  "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/2609.30793",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-25",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/awxh22qsakng8.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:25:31Z",
      "native_id": "2609.30793",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.30793"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    }
  ],
  "title": "Long-term X-ray variability of the NLS1 Ark 564",
  "title_text": "Long-term X-ray variability of the NLS1 Ark 564",
  "type": "preprint",
  "updated_at": "2026-10-30T12:25:31Z",
  "url": "https://research.draconitic.com/paper/awxh22qsakng8",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1007/s10509-026-04643-8",
      "pid": null,
      "relation": "published-as",
      "title": null,
      "venue": null
    }
  ]
}