{
  "id": "1903.08212",
  "version": "v1",
  "published": "2019-03-19T18:53:41.000Z",
  "updated": "2019-03-19T18:53:41.000Z",
  "title": "Detection of a White Dwarf companion to a Blue Straggler Star in the outskirts of globular cluster NGC 5466 with the Ultraviolet Imaging Telescope (UVIT)",
  "authors": [
    "Snehalata Sahu",
    "Annapurni Subramaniam",
    "Mirko Simunovic",
    "J. Postma",
    "Patrick Côté",
    "N. Kameswera Rao",
    "Aaron M. Geller",
    "Nathan Leigh",
    "Michael Shara",
    "Thomas H. Puzia",
    "Peter B. Stetson"
  ],
  "comment": "12 pages, 20 figures. accepted for publication in ApJ",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "We report the discovery of a hot white dwarf (WD) companion to a blue straggler star (BSS) in the globular cluster (GC) NGC 5466, based on observations from the Ultra-Violet Imaging Telescope (UVIT) on board AstroSat. The Spectral Energy Distribution (SED) of the Far-UV detected BSS NH 84 was constructed by combining the flux measurements from 4 filters of UVIT, with GALEX, GAIA and other ground-based observations. The SED of NH 84 reveals the presence of a hot companion to the BSS. The temperature and radius of the BSS (T$_{\\mathrm{eff}} = 8000^{+1000}_{-250}$ K, R/R$_\\odot = 1.44 \\pm 0.05$) derived from Gemini spectra and SED fitting using Kurucz atmospheric models are consistent with each other. The temperature and radius of the hotter companion of NH 84 (T$_{\\mathrm{eff}} = 32,000 \\pm 2000$ K, R/R$_\\odot = 0.021 \\pm 0.007$) derived by fitting Koester WD models to the SED suggest that it is likely to be a hot WD. The radial velocity derived from the spectra along with the proper motion from GAIA DR2 confirms NH 84 to be a kinematic member of the cluster. This is the second detection of a BSS-WD candidate in a GC, and the first in the outskirts of a low density GC. The location of this BSS in NGC 5466 along with its dynamical age supports the mass-transfer pathway for BSS formation in low density environments.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-03-19T18:53:41.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "blue straggler star",
      "globular cluster ngc",
      "white dwarf companion",
      "ultraviolet imaging telescope"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 12,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}