{
  "abstract": "We present the first measurement of circumgalactic dust reddening from the Vera C. Rubin Observatory, using only 4.6 deg$^2$ of ComCam Data Preview 1 --- roughly $0.03\\%$ of the final LSST footprint. Using photometric redshifts, we stack background-galaxy colors around foreground-galaxy positions and detect a chromatic reddening profile from $r_\\perp \\simeq 10$ kpc to $1$ Mpc. Interpreting average $E(g-z)$ with a Milky Way extinction curve, we find $A_V = (1.3 \\pm 0.4) \\times 10^{-1} (r_\\perp / 20 \\mathrm{kpc})^{-1.8 \\pm 0.4}$ within $120$ kpc. The amplitude and radial dependence agree with earlier Sloan Digital Sky Survey (SDSS), KiDS, and Dark Energy Survey (DES) results despite the $\\sim1000\\times$ smaller survey area and a foreground sample extending 3--6 mag fainter and 1--2 dex lower in stellar mass. The innermost 10--15 kpc bin reaches $A_V \\simeq 0.3$ mag, comparable to high-latitude extinction through the Milky Way disk near the solar circle; the steep power-law slope implies a dust distribution that does not simply trace the halo-gas profile. Splitting by rest-frame $g-r$ shows stronger extinction around red foreground galaxies (rest-frame $g-r > 0.5$), although the blue subsample is too noisy to establish a significant color dependence. This red sample, with median halo mass $5 \\times 10^{11} M_\\odot$, shows substantially more reddening within 50 kpc than previously measured around more massive LRGs and implies a dust-to-stellar-mass ratio of $\\sim 2\\%$, nearly saturating the dust budget allowed by stellar metal yields. These pathfinder data demonstrate LSST's promise for high-precision galaxy--dust measurements across galaxy mass, environment, and redshift.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2606.24159",
  "author_total": 3,
  "authors": [
    {
      "name": "John Franklin Crenshaw"
    },
    {
      "name": "Matthew McQuinn"
    },
    {
      "name": "Jessica K. Werk"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/68qrkcnhnecsw.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2606.24159",
  "fulltext_url": null,
  "id": "68qrkcnhnecsw",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2606.24159",
  "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.CO"
    ],
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7165747511",
  "pdf_url": "https://arxiv.org/pdf/2606.24159",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-14",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/68qrkcnhnecsw.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:25Z",
      "native_id": "2606.24159",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2606.24159"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.CO",
      "subfield": "cosmology"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "A First Measurement of Circumgalactic Dust Reddening from Only 4.6 deg$^2$ of the Rubin Observatory's Data Preview 1",
  "title_text": "A First Measurement of Circumgalactic Dust Reddening from Only 4.6 deg^2 of the Rubin Observatory's Data Preview 1",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:25Z",
  "url": "https://research.draconitic.com/paper/68qrkcnhnecsw",
  "venue": "arXiv",
  "versions": []
}