{
  "id": "1903.08141",
  "version": "v1",
  "published": "2019-03-19T17:55:36.000Z",
  "updated": "2019-03-19T17:55:36.000Z",
  "title": "Butterfly in a Cocoon, Understanding the origin and morphology of Globular Cluster Streams: The case of GD-1",
  "authors": [
    "Khyati Malhan",
    "Rodrigo A. Ibata",
    "Raymond G. Carlberg",
    "Monica Valluri",
    "Katherine Freese"
  ],
  "comment": "10 pages, 10 figures",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Tidally disrupted globular cluster streams are usually observed, and therefore perceived, as narrow, linear and one-dimensional structures in the 6D phase-space. Here we show that the GD-1 stellar stream, which is the tidal debris of a disrupted globular cluster, possesses a secondary diffuse and extended stellar component (~100pc wide) around it, detected at $>5\\sigma$ confidence level. Similar morphological properties are seen in synthetic streams that are produced from star clusters that are formed within dark matter sub-halos and then accreted onto a massive host galaxy. This lends credence to the idea that the progenitor of the highly retrograde GD-1 stream was originally formed outside of the Milky Way in a now defunct dark satellite galaxy. The lack of any obvious dwarf galaxy that GD-1 may be associated with suggests that at least some globular clusters form in otherwise empty dark matter sub-halos.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-03-19T17:55:36.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "morphology",
      "empty dark matter sub-halos",
      "defunct dark satellite galaxy",
      "tidally disrupted globular cluster streams",
      "globular clusters form"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 10,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}