{
  "id": "2404.04084",
  "version": "v1",
  "published": "2024-04-05T13:20:21.000Z",
  "updated": "2024-04-05T13:20:21.000Z",
  "title": "The CO-to-H$_2$ Conversion Factor in the Central Molecular Zone of the Milky Way using CO isotopologues",
  "authors": [
    "Mikito Kohno",
    "Yoshiaki Sofue"
  ],
  "comment": "15 pages, 14 figures, 3 tables, accepted for Publications of the Astronomical Society of Japan (PASJ)",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "We performed correlation analyses between the $^{12}$CO and $^{13}$CO $J=$1-0 line intensities in order to derive the variability of the CO-to-H$_2$ conversion factor ($X_{\\rm CO, iso}$) in the central molecular zone (CMZ) of our Galaxy. New high-resolution $X_{\\rm CO, iso}$ maps at a resolution of $\\sim 30$\" and the longitude-velocity diagram (LVD) at resolution $\\sim 30$\" $ \\times\\ 2$ km s$^{-1}$ are presented using the $^{12}$CO and $^{13}$CO archival survey data obtained by the Nobeyama 45 m telescope. We revealed the variation of $X_{\\rm CO, iso}$ in the CMZ within the range of $X_{\\rm CO, iso} \\sim (0.2-1.3) \\times 10^{20}\\ {\\rm cm^{-2}\\ (K\\ km\\ s^{-1})^{-1}}$, if we assume the normalization value of $0.59 \\times 10^{20}\\ {\\rm cm^{-2}\\ (K\\ km\\ s^{-1})^{-1}}$. The mean value is obtained as $X_{\\rm CO, iso} = (0.48 \\pm 0.15) \\times 10^{20}\\ {\\rm cm^{-2}\\ (K\\ km\\ s^{-1})^{-1}}$ in the CMZ of our Galaxy.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2024-04-05T13:20:21.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "central molecular zone",
      "conversion factor",
      "milky way",
      "isotopologues",
      "archival survey data"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}