{
  "abstract": "The millihertz gravitational-wave sky will be dominated by $\\sim10^{8}$ double white dwarfs while $\\sim10^{4}$ be resolvable in the Milky Way, whose three-dimensional spatial distribution traces the Galaxy's structural parameters. We present \\textsc{Galena}, a hierarchical Bayesian pipeline that recovers these parameters from a double white dwarf catalogue through an inhomogeneous Poisson-process likelihood. Each source's $3\\times3$ Galactic position covariance is computed from the waveform Fisher information matrix and propagated analytically through a $3\\times5$ Jacobian; the resulting measurement-error convolution is factored into a pre-computed sparse weight matrix, rendering the nested-sampling inference tractable. Applied to GBSIEVER-reported LISA Data Challenge sources ($N=2151$ after quality cuts), \\textsc{Galena} recovers the disk scale length $R_d=2175^{+51}_{-52}$~pc and scale height $z_d=282^{+7}_{-7}$~pc, consistent with a canonical thin disk, together with the bulge fraction $A=0.187^{+0.011}_{-0.012}$ and bulge scale radius $R_b=773^{+26}_{-25}$~pc; the bulge fraction, now recovered much closer to the literature value of $0.25$ than in our earlier exact-position fit, is measured at $\\sim6\\%$ statistical precision. An independent particle-swarm optimisation of the same likelihood reproduces these values to within a fraction of a percent, supporting the attribution of the improvement to the Fisher-matrix error propagation rather than to the sampler. The search-stage astrophysical prior improves per-source distance estimates but leaves the hierarchical inference essentially unchanged.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2609.09955",
  "author_total": 5,
  "authors": [
    {
      "name": "Shao-Dong Zhao"
    },
    {
      "name": "Xue-Hao Zhang"
    },
    {
      "name": "Qun-Ying Xie"
    },
    {
      "name": "Yu-Xiao Liu"
    },
    {
      "name": "Soumya D. Mohanty"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/8djceeedf8feh.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2609.09955",
  "fulltext_url": null,
  "id": "8djceeedf8feh",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2609.09955",
  "language": null,
  "licence": "LicenseRef-arXiv-nonexclusive-1.0",
  "licence_label": "arXiv licence",
  "licence_source": "article",
  "licence_url": "http://arxiv.org/licenses/nonexclusive-distrib/1.0/",
  "metadata_licence": "CC0-1.0",
  "native_subjects": [
    [
      "arxiv",
      "astro-ph.GA"
    ],
    [
      "arxiv",
      "astro-ph.IM"
    ],
    [
      "arxiv",
      "gr-qc"
    ],
    [
      "openalex",
      "3103|Pulsars and Gravitational Waves Research"
    ]
  ],
  "openalex": "W7212144402",
  "pdf_url": "https://arxiv.org/pdf/2609.09955",
  "pmcid": null,
  "pmid": null,
  "published": "2026-09-11",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/8djceeedf8feh.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:21:07Z",
      "native_id": "2609.09955",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2609.09955"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    },
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.IM",
      "subfield": "instrumentation-methods"
    },
    {
      "field": "physics",
      "origin": "arxiv:gr-qc",
      "subfield": "gravitation"
    }
  ],
  "title": "Milky Way Structure from Double White Dwarf Gravitational-Wave Sources",
  "title_text": "Milky Way Structure from Double White Dwarf Gravitational-Wave Sources",
  "type": "preprint",
  "updated_at": "2026-10-30T12:21:07Z",
  "url": "https://research.draconitic.com/paper/8djceeedf8feh",
  "venue": "arXiv",
  "versions": []
}