{
  "id": "2008.06089",
  "version": "v1",
  "published": "2020-08-13T19:49:01.000Z",
  "updated": "2020-08-13T19:49:01.000Z",
  "title": "Faint Stars in a Faint Galaxy: I. Ultra Deep Photometry of the Boötes I Ultra Faint Dwarf Galaxy",
  "authors": [
    "Carrie Filion",
    "Vera Kozhurina-Platais",
    "Roberto Avila",
    "Imants Platais",
    "Rosemary F. G. Wyse"
  ],
  "comment": "21 pages, 15 figures, 2 tables; accepted for publication in ApJ",
  "categories": [
    "astro-ph.GA",
    "astro-ph.IM"
  ],
  "abstract": "We present an analysis of new extremely deep images of the resolved stellar population of the Bo\\\"otes I ultra faint dwarf spheroidal galaxy. These new data were taken with the Hubble Space Telescope, using the Advanced Camera for Surveys (Wide Field Camera) and Wide Field Camera 3 (UVIS), with filters F606W and F814W (essentially V and I), as part of a program to derive the low-mass stellar initial mass function in this galaxy. We compare and contrast two approaches to obtaining the stellar photometry, namely ePSF and DAOPHOT. We identify likely members of Bo\\\"otes I based on the location of each star on the color-magnitude diagram, obtained with the DAOPHOT photometry from the ACS/WFC data. The probable members lie close to stellar isochrones that were chosen to encompass the known metallicity distribution derived from spectroscopic data of brighter radial-velocity member stars and are consistent with the main-sequence turnoff. The resulting luminosity function of the Bo\\\"otes I galaxy has a 50% completeness limit of 27.4 in F814W and 28.2 in F606W (Vega magnitude system), which corresponds to a limiting stellar mass of $\\le 0.3 M_\\odot$.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-08-13T19:49:01.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "ultra faint dwarf galaxy",
      "ultra deep photometry",
      "faint dwarf spheroidal galaxy",
      "faint galaxy",
      "faint stars"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 21,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}