{
  "abstract": "Using the fast radio bursts (FRBs) localized with the CHIME/FRB Outriggers between February and October 2025, we conduct a systematic search for dwarf host galaxies. We identify and characterize eight host galaxies for one repeating and seven apparently non-repeating FRBs, newly classifying five hosts as dwarfs with stellar masses of $\\log(M_\\ast/M_\\odot) \\approx 8.1-9.1$. We measure their gas-phase metallicities and, when combined with hosts from the literature, finding that repeating and non-repeating FRBs have statistically distinct metallicity distributions. Non-repeating FRBs inhabit relatively metal-rich environments ($12 + \\rm log( O/H) \\gtrsim 8.35$) across the full observed mass range, while repeating FRBs have significant preference for dwarf galaxies with $12 + \\rm log( O/H) \\lesssim 8.35$. Almost all repeaters associated with persistent radio sources (PRSs) are in dwarfs with $12 + \\rm log( O/H) \\lesssim 8.15$, suggesting a connection between repeaters in metal-poor dwarf environments and PRS formation. We also calculate the host dispersion measure ($\\mathrm{DM}_{\\rm host}$), Faraday rotation measure ($\\mathrm{RM}_{\\rm host}$), and scattering timescale ($τ_{\\rm host,1~GHz}$) for 54, 37, and 24 FRBs, respectively, including both our sample and FRBs in the literature. We find no significant ($>3σ$) correlation between host metallicity and $\\mathrm{DM}_{\\rm host}$, $\\mathrm{RM}_{\\rm host}$, or $τ_{\\rm host,1~GHz}$. The distinct host metallicities of apparently non-repeating and repeating FRBs may reflect metallicity-dependent massive-star evolution, with repeating FRBs and PRSs requiring more extreme magnetar birth spins than the predominantly non-repeating FRB population.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.28629",
  "author_total": 27,
  "authors": [
    {
      "name": "Y Dong"
    },
    {
      "name": "W Fong"
    },
    {
      "name": "K Nimmo"
    },
    {
      "name": "N Loudas"
    },
    {
      "name": "B.C Andersen"
    },
    {
      "name": "S Andrew"
    },
    {
      "name": "A Cai"
    },
    {
      "name": "S Chatterjee"
    },
    {
      "name": "A.M Cook"
    },
    {
      "name": "A.P Curtin"
    },
    {
      "name": "T Eftekhari"
    },
    {
      "name": "B.M Gaensler"
    },
    {
      "name": "J Hessels"
    },
    {
      "name": "V.M Kaspi"
    },
    {
      "name": "A Khan"
    },
    {
      "name": "C Leung"
    },
    {
      "name": "L Mas-Ribas"
    },
    {
      "name": "K Masui"
    },
    {
      "name": "A Moroianu"
    },
    {
      "name": "A.B Pearlman"
    },
    {
      "name": "J.X Prochaska"
    },
    {
      "name": "M.W Sammons"
    },
    {
      "name": "P Scholz"
    },
    {
      "name": "K Shin"
    },
    {
      "name": "S Simha"
    },
    {
      "name": "M Woodland"
    },
    {
      "name": "Z Zhuang"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/7nwjmwsgs80vk.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.28629",
  "fulltext_url": null,
  "id": "7nwjmwsgs80vk",
  "issns": [],
  "landing_url": "https://hal.science/hal-05830218v1",
  "language": "en",
  "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"
    ],
    [
      "arxiv",
      "astro-ph.HE"
    ],
    [
      "hal",
      "0.phys"
    ],
    [
      "hal",
      "1.phys.astr"
    ],
    [
      "openalex",
      "3103|Gamma-ray bursts and supernovae"
    ]
  ],
  "openalex": "W7214320554",
  "pdf_url": "https://arxiv.org/pdf/2609.28629",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-23",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/7nwjmwsgs80vk.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:00Z",
      "native_id": "hal-05830218",
      "source": "hal",
      "url": "https://hal.science/hal-05830218v1"
    },
    {
      "first_seen": "2026-10-30T12:24:11Z",
      "native_id": "2609.28629",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.28629"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.HE",
      "subfield": "high-energy-astrophysics"
    },
    {
      "field": "physics",
      "origin": "hal:0.phys",
      "subfield": "general"
    }
  ],
  "title": "Probing the Metallicity Dependence of Fast Radio Burst Progenitors with CHIME/FRB Outrigger Dwarf Host Galaxies",
  "title_text": "Probing the Metallicity Dependence of Fast Radio Burst Progenitors with CHIME/FRB Outrigger Dwarf Host Galaxies",
  "type": "preprint",
  "updated_at": "2026-10-30T12:24:11Z",
  "url": "https://research.draconitic.com/paper/7nwjmwsgs80vk",
  "venue": "HAL",
  "versions": []
}