{
  "id": "1504.07239",
  "version": "v1",
  "published": "2015-04-27T20:00:37.000Z",
  "updated": "2015-04-27T20:00:37.000Z",
  "title": "Mapping the Outer Edge of the Young Stellar Cluster in the Galactic Center",
  "authors": [
    "Morten N. Støstad",
    "Tuan Do",
    "Norm Murray",
    "Jessica R. Lu",
    "Sylvana Yelda",
    "Andrea M. Ghez"
  ],
  "comment": "17 pages, 11 figures, 3 tables, ApJ accepted",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We present new near-infrared spectroscopic observations of the outer edges of the young stellar cluster around the supermassive black hole at the Galactic center. The observations show a break in the surface-density profile of young stars at approximately 13 arcsec (0.52 pc). These observations spectroscopically confirm previous suggestions of a break based on photometry. Using Gemini North's Near-Infrared Integral Field Spectrometer (NIFS) we are able to detect and separate early- and late-type stars with a 75% completeness at Ks = 15.5. We sample a region with radii between 7\" to 23\" (0.28 pc to 0.92 pc) from Sgr A*, and present new spectral classifications of 144 stars brighter than Ks = 15.5, where 140 stars are late-type (> 1 Gyr) and only four stars are early-type (young, 4-6 Myr). A broken power-law fit of the early-type surface-density matches well with our data and previously published values. The projected surface-density of late-type stars is also measured and found to be consistent with previous results. We find that the observed early-type surface-density profile is inconsistent with the theory of the young stars originating from a tightly bound infalling cluster, as no significant trail of young stars is found at radii above 13\". We also note that either a simple disk instability criterion or a cloud-cloud collision could explain the location of the outer edge, though we lack information to make conclusive remarks on either alternative. If this break in surface-density represents an edge to the young stellar cluster it would set an important scale for the most recent episode of star formation at the Galactic center.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2015-04-27T20:00:37.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "young stellar cluster",
      "outer edge",
      "galactic center",
      "young stars",
      "surface-density"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 17,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}