{
  "id": "2204.09699",
  "version": "v1",
  "published": "2022-04-20T18:00:03.000Z",
  "updated": "2022-04-20T18:00:03.000Z",
  "title": "Distances to Local Group Galaxies via Population II, Stellar Distance Indicators. II. The Fornax Dwarf Spheroidal",
  "authors": [
    "Elias K. Oakes",
    "Taylor J. Hoyt",
    "Wendy L. Freedman",
    "Barry F. Madore",
    "Quang H. Tran",
    "William Cerny",
    "Rachael L. Beaton",
    "Mark Seibert"
  ],
  "comment": "17 pages, 11 figures, 4 tables; published in the Astrophysical Journal",
  "journal": "ApJ, 929, 116 (2022)",
  "doi": "10.3847/1538-4357/ac5b07",
  "categories": [
    "astro-ph.GA",
    "astro-ph.CO"
  ],
  "abstract": "We determine three independent Population II distance moduli to the Fornax dwarf spheroidal (dSph) galaxy, using wide-field, ground-based $VI$ imaging acquired with the Magellan-Baade telescope at Las Campanas Observatory. After subtracting foreground stars using Gaia EDR3 proper motions, we measure an $I$-band tip of the red giant branch (TRGB) magnitude of $I_0^\\mathrm{TRGB} = 16.753 \\pm 0.03_\\mathrm{stat} \\pm 0.037_\\mathrm{sys}$ mag, with a calibration based in the LMC giving a distance modulus of $\\mu_0^\\mathrm{TRGB} = 20.80 \\pm 0.037_\\mathrm{stat} \\pm 0.057_\\mathrm{sys}$ mag. We determine an RR Lyrae (RRL) distance from template mean magnitudes, with periods adopted from the literature. Adopting a Gaia DR2 calibration of first overtone RRL period-luminosity and period-Wesenheit relations, we find $\\mu_0^\\mathrm{PLZ} = 20.74 \\pm 0.01_\\mathrm{stat} \\pm 0.12_\\mathrm{sys}$ mag and $\\mu_0^\\mathrm{PWZ} = 20.68 \\pm 0.02_\\mathrm{stat} \\pm 0.07_\\mathrm{sys}$ mag. Finally, we determine a distance from Fornax's horizontal branch (HB) and two galactic globular cluster calibrators, giving $\\mu_0^\\mathrm{HB} = 20.83 \\pm 0.03_\\mathrm{stat} \\pm 0.09_\\mathrm{sys}$ mag. These distances are each derived from homogeneous IMACS photometry, are anchored to independent geometric zero-points, and utilize different classes of stars. We therefore average over independent uncertainties and report the combined distance modulus $\\langle \\mu_0\\rangle = 20.770 \\pm 0.042_\\mathrm{stat} \\pm 0.024_\\mathrm{sys}$ mag (corresponding to a distance of $143\\pm3$ kpc).",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-04-20T18:00:03.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "fornax dwarf spheroidal",
      "local group galaxies",
      "stellar distance indicators",
      "distance modulus",
      "population"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}