{
  "abstract": "We present a spectroscopic study of the lensed quasar Q2237+0305, the Einstein Cross, assessing the best wavelength coverage to date with the X-shooter instrument (from $3000$ to $20000$ $\\mathring{A}$), and thus improving the available spectroscopic data for this system. Using as a reference the characteristic emission lines for each quasar macro-image, we estimate the chromatic microlensing effect between pairs of images and calculate the extinction curve, confirming no significant differences between spectra $C$ and $A$ caused by extinction in the lens galaxy. In addition, we model the accretion disk characterized by a temperature profile with logarithmic slope $1/p$ and size $r_{s}$, assuming a thin-disk model with a power-law function of the form $r_{s}$ $\\propto$ $λ^{p}$. To do this, we calculated a set of three chromatic microlensing measurements compiling previous estimates from the literature to test the wavelength dependence. This temperature profile was also compared to the canonical thin-disk model with $p=4/3$. Finally, we estimated the likelihood between the disk model and the observed data collected from multiple epochs through mock microlensing magnification maps and determined the probability density functions of each parameter from a Bayesian analysis. As a result, our estimated values for the accretion disk size and its exponential index are $r_{s}=4.9^{+2.3}_{-2.6}$ $\\sqrt{M/0.3M_{\\odot}}$ (lt-day) and $p=0.77^{+0.47}_{-0.28}$, respectively, reinforcing a departure from the standard accretion disk model ($ T \\propto r_s^{-3/4}$).",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2611.12448",
  "author_total": 4,
  "authors": [
    {
      "name": "R. Jerez-Nicurcar"
    },
    {
      "name": "A. Esteban-Gutiérrez"
    },
    {
      "name": "V. Motta"
    },
    {
      "name": "E. Mediavilla"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/4w4tzbhxatgbv.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2611.12448",
  "fulltext_url": null,
  "id": "4w4tzbhxatgbv",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2611.12448",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "http://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ]
  ],
  "openalex": null,
  "pdf_url": "https://arxiv.org/pdf/2611.12448",
  "pmcid": null,
  "pmid": null,
  "published": "2026-11-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/4w4tzbhxatgbv.ris",
  "sources": [
    {
      "first_seen": "2026-11-10T06:21:23Z",
      "native_id": "2611.12448",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2611.12448"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Revisiting the Einstein Cross with X-shooter spectra: New estimates of accretion disk parameters and broad emission line profiles from microlensing",
  "title_text": "Revisiting the Einstein Cross with X-shooter spectra: New estimates of accretion disk parameters and broad emission line profiles from microlensing",
  "type": "preprint",
  "updated_at": "2026-11-10T06:21:23Z",
  "url": "https://research.draconitic.com/paper/4w4tzbhxatgbv",
  "venue": "arXiv",
  "versions": [
    {
      "doi": "10.1051/0004-6361/202660452",
      "pid": "cnnp8mbxyw7ap",
      "relation": "published-as",
      "title": "Revisiting the Einstein Cross with X-shooter spectra: New estimates of accretion disk parameters and broad emission line profiles from microlensing",
      "venue": "Astronomy & Astrophysics"
    }
  ]
}