{
  "id": "1312.3181",
  "version": "v1",
  "published": "2013-12-11T14:19:38.000Z",
  "updated": "2013-12-11T14:19:38.000Z",
  "title": "Trigonometric parallaxes to star-forming regions within 4 kpc of the galactic center",
  "authors": [
    "A. Sanna",
    "M. J. Reid",
    "K. M. Menten",
    "T. M. Dame",
    "B. Zhang",
    "M. Sato",
    "A. Brunthaler",
    "L. Moscadelli",
    "K. Immer"
  ],
  "comment": "31 pages, 9 figures, 4 tables, accepted by The Astrophysical Journal",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We report four trigonometric parallaxes for high-mass star-forming regions within 4 kpc of the Galactic center. These measurements were made with the VLBA as part of the BeSSeL Survey. By associating these sources kinematically with large-scale features in CO and HI longitude-velocity diagrams, we begin to outline some major features of the inner Milky Way: the Connecting arm, the near and far 3 kpc arms, and the Norma arm. The Connecting arm in the first Galactic quadrant lies closer to the Galactic center than the far 3 kpc arm and is offset by the long-bar's major axis near its leading edge, supporting the presence of an inner Lindblad resonance. Assuming the 3 kpc arms are a continuous physical structure, the relative Galactocentric distance of its near and far sides suggests highly elliptical streamlines of gas around the bar(s) and a bar corotation radius, r_CR > 3.6 kpc. At a Galactic longitude near 10{\\deg} and a heliocentric distance of about 5 kpc, the near 3 kpc arm and the Norma arm intersect on a face-on view of our Galaxy, while passing at different Galactic latitudes. We provide an accurate distance measurement to the W31 star-forming complex of 4.95 (+0.5;-0.43) kpc from the Sun, which associates it with a bright CO feature belonging to the near 3 kpc arm.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-12-11T14:19:38.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galactic center",
      "kpc arm",
      "trigonometric parallaxes",
      "star-forming regions",
      "first galactic quadrant lies closer"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/781/2/108",
      "journal": "The Astrophysical Journal",
      "year": 2014,
      "month": "Feb",
      "volume": 781,
      "number": 2,
      "pages": 108
    },
    "note": {
      "typesetting": "TeX",
      "pages": 31,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "adsabs": "2014ApJ...781..108S"
    }
  }
}