{
  "id": "0909.3857",
  "version": "v1",
  "published": "2009-09-21T20:08:49.000Z",
  "updated": "2009-09-21T20:08:49.000Z",
  "title": "The Structure of the Outer Galactic Disc as revealed by IPHAS early A Stars",
  "authors": [
    "S. E. Sale",
    "J. E. Drew",
    "C. Knigge",
    "A. A. Zijlstra",
    "M. J. Irwin",
    "R. A. H. Morris",
    "S. Phillipps",
    "J. J. Drake",
    "R. Greimel",
    "Y. C. Unruh",
    "P. J. Groot",
    "A. Mampaso",
    "N. A. Walton"
  ],
  "comment": "11 pages, accepted for publication in MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "This study is an investigation of the stellar density profile of the Galactic disc in the Anticentre direction. We select over 40,000 early A stars from IPHAS photometry in the Galactic longitude range 160 < l < 200 close to the equatorial plane (-1 < b < +1). We then compare their observed reddening-corrected apparent magnitude distribution with simulated photometry obtained from parameterised models in order to set constraints on the Anticentre stellar density profile. By selecting A stars, we are appraising the properties of a population only ~100 Myrs old. We find the stellar density profile of young stars is well fit to an exponential with length scale of (3020 \\pm 120_{statistical} \\pm 180_{systematic}) pc, which is comparable to that obtained in earlier studies, out to a Galactocentric radius of R_T = (13.0 \\pm 0.5_{statistical} \\pm 0.6_{systematic}) kpc. At larger radii the rate of decline appears to increase with the scale length dropping to (1200 \\pm 300_{statistical} \\pm 70_{systematic}) pc. This result amounts to a refinement of the conclusions reached in previous studies that the stellar density profile is abruptly truncated. The IPHAS A star data are not compatible with models that propose a sudden change in metallicity at R_G = 10 kpc.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2009-09-21T20:08:49.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "outer galactic disc",
      "stellar density profile",
      "anticentre stellar density",
      "reddening-corrected apparent magnitude distribution"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1111/j.1365-2966.2009.15746.x",
      "journal": "Monthly Notices of the Royal Astronomical Society",
      "year": 2010,
      "month": "Feb",
      "volume": 402,
      "number": 2,
      "pages": 713
    },
    "note": {
      "typesetting": "TeX",
      "pages": 11,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 831819,
      "adsabs": "2010MNRAS.402..713S"
    }
  }
}