{
  "abstract": "We present a statistical study of the cool circumgalactic medium (CGM) around massive post-starburst galaxies, traced by Mg II $λ\\lambda2796,2803$ absorption in background quasar spectra from the Dark Energy Spectroscopic Instrument (DESI) Data Release 2. Cross-matching ~1.98 million quasar sightlines with luminous red galaxies at $0.4 < z < 0.76$ with stellar masses between $10.6 < \\log_{10}(M_*/\\mathrm{M}_\\odot) < 12$ yields ~143 million galaxy-quasar pairs, 50-60 times more per impact-parameter bin than our previous SDSS-based analysis. We stack the Mg II absorption as a function of projected separation and classify the foreground galaxies using mean-field independent component analysis (MFICA), further subdividing the post-starburst population into sub-samples ordered by time since the starburst. The mean Mg II equivalent width declines with impact parameter for every class. Post-starburst galaxies show the strongest absorption of any spectral class, reaching $W_{\\rm MgII} = 1.58 \\pm 0.32$ Å within 71 kpc, well above star-forming ($0.69 \\pm 0.15$ Å) and quiescent ($0.22 \\pm 0.05$ Å) galaxies of comparable stellar mass at the same projected separation. Within the post-starburst phase the absorption profile evolves systematically: the youngest systems show the highest, most centrally concentrated absorption and the steepest radial decline, whereas progressively older systems show weaker inner absorption and enhanced absorption at intermediate radii (~300-1000 kpc). Independent Bagpipes star-formation-history fitting confirms that this ordering corresponds to an ageing sequence. We interpret this evolution as the outward redistribution of cool gas expelled by feedback-driven winds, consistent with characteristic outflow velocities of a few hundred km s$^{-1}$, with a residual inner cool-gas reservoir persisting throughout the post-starburst phase.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.41681",
  "author_total": 48,
  "authors": [
    {
      "name": "Zoe Harvey"
    },
    {
      "name": "Sahyadri Krishna"
    },
    {
      "name": "Rita Tojeiro"
    },
    {
      "name": "Vivienne Wild"
    },
    {
      "name": "Jessica Nicole Aguilar"
    },
    {
      "name": "Steven Ahlen"
    },
    {
      "name": "Eric Armengaud"
    },
    {
      "name": "Florian Beutler"
    },
    {
      "name": "Davide Bianchi"
    },
    {
      "name": "David Brooks"
    },
    {
      "name": "Rebecca Canning"
    },
    {
      "name": "Aurelio Carnero Rosell"
    },
    {
      "name": "Todd Claybaugh"
    },
    {
      "name": "Andrei Cuceu"
    },
    {
      "name": "Axel de la Macorra"
    },
    {
      "name": "Peter Doel"
    },
    {
      "name": "Jaime E. Forero-Romero"
    },
    {
      "name": "Enrique Gaztañaga"
    },
    {
      "name": "Satya Gontcho A Gontcho"
    },
    {
      "name": "Gaston Gutierrez"
    },
    {
      "name": "ChangHoon Hahn"
    },
    {
      "name": "Hiram K. Herrera-Alcantar"
    },
    {
      "name": "Stephanie Juneau"
    },
    {
      "name": "Robert Kehoe"
    },
    {
      "name": "Martin Landriau"
    },
    {
      "name": "Laurent Le Guillou"
    },
    {
      "name": "Marc Manera"
    },
    {
      "name": "Aaron Meisner"
    },
    {
      "name": "Ramon Miquel"
    },
    {
      "name": "John Moustakas"
    },
    {
      "name": "Adam Myers"
    },
    {
      "name": "Seshadri Nadathur"
    },
    {
      "name": "Jeffrey A. Newman"
    },
    {
      "name": "Enrique Paillas"
    },
    {
      "name": "Will Percival"
    },
    {
      "name": "Ignasi Pérez-Ràfols"
    },
    {
      "name": "Francisco Prada"
    },
    {
      "name": "Corentin Ravoux"
    },
    {
      "name": "Graziano Rossi"
    },
    {
      "name": "Rossana Ruggeri"
    },
    {
      "name": "Eusebio Sanchez"
    },
    {
      "name": "Christoph Saulder"
    },
    {
      "name": "David Schlegel"
    },
    {
      "name": "Joseph Harry Silber"
    },
    {
      "name": "Małgorzata Siudek"
    },
    {
      "name": "Gregory Tarlé"
    },
    {
      "name": "Benjamin Alan Weaver"
    },
    {
      "name": "Hu Zou"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/5h5kk595mpa29.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.41681",
  "fulltext_url": null,
  "id": "5h5kk595mpa29",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.41681",
  "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/2610.41681",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-30",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/5h5kk595mpa29.ris",
  "sources": [
    {
      "first_seen": "2026-11-02T12:21:15Z",
      "native_id": "2610.41681",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.41681"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "The Evolution of the Circumgalactic Medium after a starburst in DESI Post-Starburst Galaxies",
  "title_text": "The Evolution of the Circumgalactic Medium after a starburst in DESI Post-Starburst Galaxies",
  "type": "preprint",
  "updated_at": "2026-11-04T15:20:51Z",
  "url": "https://research.draconitic.com/paper/5h5kk595mpa29",
  "venue": "arXiv",
  "versions": []
}