{
  "id": "1810.13139",
  "version": "v1",
  "published": "2018-10-31T07:52:15.000Z",
  "updated": "2018-10-31T07:52:15.000Z",
  "title": "The radial distribution of Blue stragglers in Galactic Globular Cluster NGC 6656 $-$ Clues on the dynamical status",
  "authors": [
    "Gaurav Singh",
    "R. K. S. Yadav"
  ],
  "categories": [
    "astro-ph.SR",
    "astro-ph.GA"
  ],
  "abstract": "We present dynamical status of the Galactic globular cluster NGC 6656 using spatial distribution of Blue Straggler Stars (BSSs). A combination of multi-wavelength high-resolution space and ground-based data are used to cover a large cluster region. We determine the centre of gravity ($C_{grav}$) and construct the projected density profile of the cluster using the probable cluster members selected from \\textit{HST} and \\textit{Gaia} DR2 proper motion data sets. The projected density profile in the investigated region is nicely reproduced by a single mass King model, with core ($r_{c}$) and tidal ($r_{t}$) radius as $75\\arcsec.2$ $\\pm$ $3\\arcsec.1$ and $35\\arcmin.6$ $\\pm$ $1\\arcmin.1$ respectively. In total, 90 BSSs are identified on the basis of proper motion data in the region of radius $625\\arcsec$. An average mass of the BSSs is determined as $1.06$ $\\pm$ $0.09$ $M_{\\sun}$ and with an age range of 0.5 to 7 Gyrs. The BSS radial distribution shows a bimodal trend, with a peak in the centre, a minimum at $r \\sim r_c$ and a rising tendency in the outer region. The BSS radial distribution shows a flat behaviour in the outermost region of the cluster. We also estimate $A^{+}_{rh}$ parameter as an alternative indicator of the dynamical status of the cluster and is found to be $0.038$ $\\pm$ $0.016$. Based on the radial distribution and $A^{+}_{rh}$ parameter, we conclude that NGC 6656 is an intermediate dynamical age cluster.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2018-10-31T07:52:15.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "galactic globular cluster ngc",
      "dynamical status",
      "blue straggler",
      "proper motion data sets",
      "bss radial distribution"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}