{
  "id": "1304.2953",
  "version": "v1",
  "published": "2013-04-10T13:27:27.000Z",
  "updated": "2013-04-10T13:27:27.000Z",
  "title": "The velocity dispersion profile of NGC 6388 from resolved-star spectroscopy: no evidence of a central cusp and new constraints on the black hole mass",
  "authors": [
    "B. Lanzoni",
    "A. Mucciarelli",
    "L. Origlia",
    "M. Bellazzini",
    "F. R. Ferraro",
    "E. Valenti",
    "P. Miocchi",
    "E. Dalessandro",
    "C. Pallanca",
    "D. Massari",
    "-"
  ],
  "comment": "Accepted for publication by ApJ; 38 pages, 3 tables, 15 figures",
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "By combining high spatial resolution and wide-field spectroscopy performed, respectively, with SINFONI and FLAMES at the ESO/VLT we measured the radial velocities of more than 600 stars in the direction of NGC 6388, a Galactic globular cluster which is suspected to host an intermediate-mass black hole. Approximately 55% of the observed targets turned out to be cluster members. The cluster velocity dispersion has been derived from the radial velocity of individual stars: 52 measurements in the innermost 2\", and 276 stars located between 18\" and 600\". The velocity dispersion profile shows a central value of ~13 km/s, a flat behavior out to ~60\" and a decreasing trend outwards. The comparison with spherical and isotropic models shows that the observed density and velocity dispersion profiles are inconsistent with the presence of a central black hole more massive than ~2000 Msol. These findings are at odds with recent results obtained from integrated light spectra, showing a velocity dispersion profile with a steep central cusp of 23-25 km/s at r<2\" and suggesting the presence of a black hole with a mass of 17,000 Msol (Lutzgendorf et al. 2011). We also found some evidence of systemic rotation with amplitude Arot ~8 km/s in the innermost 2\" (0.13 pc), decreasing to Arot= 3.2 km/s at 18\"<r<160\".",
  "revisions": [
    {
      "version": "v1",
      "updated": "2013-04-10T13:27:27.000Z"
    }
  ],
  "resources": [
    {
      "type": "1",
      "source": "1",
      "title": "Mr.",
      "href": "1",
      "status": "public"
    }
  ],
  "analyses": {
    "keywords": [
      "velocity dispersion profile",
      "black hole mass",
      "central cusp",
      "resolved-star spectroscopy",
      "constraints"
    ],
    "tags": [
      "journal article"
    ],
    "publication": {
      "doi": "10.1088/0004-637X/769/2/107",
      "journal": "The Astrophysical Journal",
      "year": 2013,
      "month": "Jun",
      "volume": 769,
      "number": 2,
      "pages": 107
    },
    "note": {
      "typesetting": "TeX",
      "pages": 38,
      "language": "en",
      "license": "arXiv",
      "status": "editable",
      "inspire": 1227771,
      "adsabs": "2013ApJ...769..107L"
    }
  }
}