{
  "id": "0905.0627",
  "version": "v2",
  "published": "2009-05-05T16:15:27.000Z",
  "updated": "2009-12-09T19:25:16.000Z",
  "title": "New Limits on an Intermediate Mass Black Hole in Omega Centauri: I. Hubble Space Telescope Photometry and Proper Motions",
  "authors": [
    "Jay Anderson",
    "Roeland P. van der Marel"
  ],
  "comment": "27 pages, 28 figures, ApJ in press. v2 includes additions in response to referee comments",
  "journal": "Astrophys.J.710:1032-1062,2010",
  "doi": "10.1088/0004-637X/710/2/1032",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "We analyze data from the Hubble Space Telescope's Advanced Camera for Surveys of the globular cluster Omega Cen. We construct a photometric and proper-motion catalog using the GO-9442, GO-10252, and GO-10775 data sets. The 2.5- to 4-year baseline between observations yields a catalog of some 10^5 proper motions, with 53,382 high-quality measurements in a central field. We determine the cluster center to ~1-arcsecond accuracy using two different star-count methods, and a completely independent method using 2MASS images. We also determine the kinematical center of the proper motions, which agrees with the star-count center to within its uncertainty. The proper-motion dispersion of the cluster increases gradually inwards, but there is no variation in kinematics with position within the central ~15 arcsec: there is no dispersion cusp and no stars with unusually high velocities. We measure for the first time in any globular cluster the variation in proper-motion dispersion with mass along the main sequence, and find the cluster not yet to be in equipartition. Our proper-motion results do not confirm the arguments put forward by Noyola, Gebhardt & Bergmann to suspect an intermediate-mass black hole (IMBH) in Omega Cen. In Paper II we present new dynamical models for the high-quality data presented here, with the aim of putting quantitative contraints on the mass of any possible IMBH.",
  "revisions": [
    {
      "version": "v2",
      "updated": "2009-12-09T19:25:16.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "intermediate mass black hole",
      "hubble space telescope photometry",
      "proper motions",
      "omega centauri",
      "space telescopes advanced camera"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "journal": "The Astrophysical Journal",
      "year": 2010,
      "month": "Feb",
      "volume": 710,
      "number": 2,
      "pages": 1032
    },
    "note": {
      "typesetting": "TeX",
      "pages": 27,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 819449,
      "adsabs": "2010ApJ...710.1032A"
    }
  }
}