{
  "abstract": "Blue horizontal-branch (BHB) stars are ideal tracers for mapping the structure of the Galactic stellar halo. However, traditional spectroscopic identification is limited by data quality and sample size, while broad-band photometric methods often achieve only moderate completeness and purity. Building upon the color-space BHB identification method of \\citet{2025ApJS..278...62H}, we synthesize SkyMapper $(u,v,g,z)$ photometry from DESI MWS DR1 spectroscopy and identify 9,237 BHB candidates in the $(g-z)_0$--$(u-v)_0$ color space using the HDBSCAN clustering algorithm. We then construct a Kernel Density Estimation (KDE) Bayesian probability model with capture-recapture (C-R) prior to assign posterior membership probabilities, achieving a probability-weighted purity of 88.9\\% and completeness of 94.2\\%. Applying an escape-velocity cut based on the Galactic gravitational potential, we remove 1,461 contaminants with unphysical kinematic parameters, yielding a clean photometric BHB sample $\\mathcal{S}_c$ of 7,776 stars (retention rate $R_{\\rm keep} = 84.2\\%$). Systematic analysis of the contaminants reveals that they are predominantly faint sources ($g\\sim20$~mag) with very low signal-to-noise ratios (median SNR~$<$~5). When the BHB color--luminosity relation is incorrectly applied to these objects, their space velocities are amplified beyond the Galactic escape limit, confirming that the escape-velocity filter essentially acts as a physical detector of low-SNR--driven distance inflation.",
  "abstract_shown": true,
  "affiliations": [],
  "article_type": null,
  "arxiv": "2610.15031",
  "author_total": 8,
  "authors": [
    {
      "name": "Shuai Zhang"
    },
    {
      "name": "Xiaolong Wang"
    },
    {
      "name": "Kai Xiao"
    },
    {
      "name": "Guozhen Hu"
    },
    {
      "name": "Wenyuan Cui"
    },
    {
      "name": "Ce Cai"
    },
    {
      "name": "Shuai Feng"
    },
    {
      "name": "Jie Ju"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/d7zk7awrws379.bib",
  "cited_by": 0,
  "doi": "10.48550/arxiv.2610.15031",
  "fulltext_url": null,
  "id": "d7zk7awrws379",
  "issns": [],
  "landing_url": "https://arxiv.org/abs/2610.15031",
  "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/2610.15031",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-10",
  "publisher": null,
  "ris": "https://research.draconitic.com/paper/d7zk7awrws379.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:29:06Z",
      "native_id": "2610.15031",
      "source": "arxiv",
      "url": "https://arxiv.org/abs/2610.15031"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "arxiv:astro-ph.GA",
      "subfield": "galaxies"
    }
  ],
  "title": "Photometric Identification and Dynamical Purification of Blue Horizontal Branch Stars in DESI MWS DR1",
  "title_text": "Photometric Identification and Dynamical Purification of Blue Horizontal Branch Stars in DESI MWS DR1",
  "type": "preprint",
  "updated_at": "2026-10-30T12:29:06Z",
  "url": "https://research.draconitic.com/paper/d7zk7awrws379",
  "venue": "arXiv",
  "versions": []
}