{
  "abstract": "Most known quasars at $z>6$ were selected through their rest-frame UV emission. Only a small number of reddened quasars have been identified at these redshifts, leaving their nuclear and host-galaxy properties poorly constrained. We present JWST/NIRSpec spectroscopy and ALMA band 6 observations of the quasar J1440+0019 at $z=6.5488$, revealing its dust-reddened nature and jointly characterizing its nucleus and host galaxy. The continuum is best described by an SMC-like extinction law with $E(B-V)=0.20\\pm0.03$. Three absorption systems detected in N V, Si IV, and C IV are blueshifted by approximately $900$--$3600$ km s$^{-1}$ and likely trace an ionized nuclear outflow. The broad Mg II line and extinction-corrected continuum yield a black-hole mass of $\\log(M_{\\rm BH}/M_\\odot)=9.04\\pm0.42$, a bolometric luminosity of $L_{\\rm bol}\\simeq1.1\\times10^{47}$ erg s$^{-1}$, and an Eddington ratio of $λ_{\\rm Edd}\\simeq0.8$. ALMA observations further reveal its host galaxy to be among the most [C II]-luminous known at $z>6$, with $L_{\\mathrm{[C II]}}=(7.21\\pm0.25)\\times10^9 L_\\odot$. For a fiducial dust temperature of 47 K and emissivity index $β=1.6$, the dust continuum implies $L_{\\rm TIR}=8.9\\times10^{12} L_\\odot$ and $M_{\\rm dust}=4.0\\times10^8 M_\\odot$. The inferred dynamical mass places J1440+0019 in the region of the $M_{\\rm BH}$--$M_{\\rm dyn}$ plane occupied by high-redshift blue quasars. These observations reveal a moderately reddened, rapidly accreting quasar in a luminous, dust-rich host during reionization. Its measured nuclear and host-galaxy properties provide an observational reference for identifying and characterizing similar systems in future systematic searches with wide-area infrared surveys.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.13758",
  "author_total": 21,
  "authors": [
    {
      "name": "Daming Yang"
    },
    {
      "name": "Joseph F. Hennawi"
    },
    {
      "name": "Rychard Bouwens"
    },
    {
      "name": "Timo Kist"
    },
    {
      "name": "Eduardo Bañados"
    },
    {
      "name": "Hiddo S. B. Algera"
    },
    {
      "name": "Aaron J. Barth"
    },
    {
      "name": "Sarah E. I. Bosman"
    },
    {
      "name": "Frederick B. Davies"
    },
    {
      "name": "Anna-Christina Eilers"
    },
    {
      "name": "Xiaohui Fan"
    },
    {
      "name": "Victoria A. Fawcett"
    },
    {
      "name": "Yuming Fu"
    },
    {
      "name": "Anniek J. Gloudemans"
    },
    {
      "name": "Francesco Guarneri"
    },
    {
      "name": "Bin Jia"
    },
    {
      "name": "Elia Pizzati"
    },
    {
      "name": "Huub Röttgering"
    },
    {
      "name": "Jan-Torge Schindler"
    },
    {
      "name": "Feige Wang"
    },
    {
      "name": "Jinyi Yang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/9t9swknfdgz41.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.13758",
  "fulltext_url": null,
  "id": "9t9swknfdgz41",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.13758",
  "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",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7221569258",
  "pdf_url": "https://arxiv.org/pdf/2610.13758",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/9t9swknfdgz41.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:28:36Z",
      "native_id": "2610.13758",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.13758"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "A dust-reddened quasar in a [C II]-luminous host at z=6.55",
  "title_text": "A dust-reddened quasar in a [C II]-luminous host at z=6.55",
  "type": "preprint",
  "updated_at": "2026-10-30T12:28:36Z",
  "url": "https://research.draconitic.com/paper/9t9swknfdgz41",
  "venue": "arXiv",
  "versions": []
}