{
  "abstract": "We present a homogeneous metallicity analysis of old stellar populations in the Local Volume galaxies using data from the color–magnitude diagrams/tip of the red giant branch (TRGB) catalog of the Extragalactic Distance Database ( http://edd.ifa.hawaii.edu ), which provides uniformly measured TRGB distances and point-spread function photometry for resolved stars in over 500 nearby galaxies observed with the Hubble Space Telescope. We apply the calibration of M. G. Lee et al. to estimate the mean metallicity [Fe/H] from the ( V − I ) color of the red giant branch (RGB) at M I = −3.5 mag obtaining reliable measurements for 334 galaxies out of an initial set of 558. The RGB-Colors were derived by locating the maximum stellar density in the ( M I , ( V − I )) diagram, smoothed with a Gaussian kernel and refined via Monte Carlo simulations (500–1000 realizations), yielding typical uncertainties of about 0.03 mag. Our results show that most galaxies lie within the color range ( V − I ) = 1.22−1.74 of the original calibration, corresponding to metal-poor systems typical of dwarfs, with the overall metallicity distribution peaking at [Fe/H] = −1.89 ± 0.03 dex. We find a pronounced luminosity–metallicity relation across a wide magnitude range, from faint dwarfs ( M B > −7) mag to giant galaxies ( M B < −18), described by the regression [Fe/H] = −2.6−0.075 M B . At the same time, on the luminosity–metallicity plane, dwarf spheroidals occupy the higher-metallicity region, which may reflect the age–metallicity degeneracy in RGB-based metallicity determinations. Both dwarf and giant galaxies follow the same relation, though ACS fields for giants often sample outer, more metal-poor regions.",
  "abstract_shown": true,
  "affiliations": [
    "Special Astrophysical Observatory of the Russian Academy of Sciences",
    "Saint Petersburg State University",
    "University of Hawaii",
    "Space Telescope Science Institute"
  ],
  "article_type": null,
  "arxiv": null,
  "author_total": 4,
  "authors": [
    {
      "affs": [
        0
      ],
      "name": "Lidia N. Makarova",
      "orcid": "0000-0003-0736-7609"
    },
    {
      "affs": [
        0,
        1
      ],
      "name": "Denis G. Purytin",
      "orcid": "0009-0008-5135-071X"
    },
    {
      "affs": [
        2
      ],
      "name": "R. Brent Tully",
      "orcid": "0000-0002-9291-1981"
    },
    {
      "affs": [
        3
      ],
      "name": "Gagandeep S. Anand",
      "orcid": "0000-0002-5259-2314"
    }
  ],
  "bibtex": "https://research.draconitic.com/paper/2h2yns8kt1e41.bib",
  "cited_by": 0,
  "doi": "10.3847/1538-3881/aea78c",
  "fulltext_url": null,
  "id": "2h2yns8kt1e41",
  "issns": [
    "0004-6256",
    "1538-3881"
  ],
  "landing_url": "https://iopscience.iop.org/article/10.3847/1538-3881/aea78c",
  "language": null,
  "licence": "CC-BY-4.0",
  "licence_label": "CC BY 4.0",
  "licence_source": "article",
  "licence_url": "https://creativecommons.org/licenses/by/4.0/",
  "metadata_licence": null,
  "native_subjects": [
    [
      "openalex",
      "3103|Galaxies: Formation, Evolution, Phenomena"
    ]
  ],
  "openalex": "W7155086817",
  "pdf_url": "https://iopscience.iop.org/article/10.3847/1538-3881/aea78c/pdf",
  "pmcid": null,
  "pmid": null,
  "published": "2026-10-09",
  "publisher": "American Astronomical Society",
  "ris": "https://research.draconitic.com/paper/2h2yns8kt1e41.ris",
  "sources": [
    {
      "first_seen": "2026-10-30T12:18:14Z",
      "native_id": "10.3847/1538-3881/aea78c",
      "source": "crossref",
      "url": "https://iopscience.iop.org/article/10.3847/1538-3881/aea78c"
    }
  ],
  "subjects": [
    {
      "field": "astronomy",
      "origin": "openalex:3103|Galaxies: Formation, Evolution, Phenomena",
      "subfield": "galaxies"
    }
  ],
  "title": "The Metal Content of Resolved Galaxies",
  "title_text": "The Metal Content of Resolved Galaxies",
  "type": "peer-reviewed",
  "updated_at": "2026-10-30T12:18:14Z",
  "url": "https://research.draconitic.com/paper/2h2yns8kt1e41",
  "venue": "The Astronomical Journal",
  "versions": []
}