{
  "id": "2304.01610",
  "version": "v1",
  "published": "2023-04-04T08:06:08.000Z",
  "updated": "2023-04-04T08:06:08.000Z",
  "title": "$^{18}$O$/^{17}$O abundance ratio toward a sample of massive star forming regions with parallax distances",
  "authors": [
    "Chao Ou",
    "Junzhi Wang",
    "Siqi Zheng",
    "Juan Li",
    "Donatella Romano",
    "Zhi-Yu Zhang"
  ],
  "comment": "15 pages, 5 figures, 1 table, Accepted for publication in MNRAS",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "The $^{18}$O$/^{17}$O abundance ratio is, in principle, a powerful tool to estimate the relative contributions of massive stars and low- to intermediate-mass stars to the chemical enrichment of galaxies. We present $^{18}$O$/^{17}$O ratios derived from simultaneous observations of C$^{18}$O and C$^{17}$O 1-0 toward fifty-one massive star forming regions with the Institut de Radioastronomie Millim\\'etrique (IRAM) 30 meter telescope. Simultaneous observations of HC$^{18}$O$^{+}$ 1-0 and HC$^{17}$O$^{+}$ 1-0 with the Yebes 40m telescope toward five sources from this sample were also done to test the consistency of $^{18}$O$/^{17}$O ratios derived from different isotopic pairs. From our improved measurements, resulting in smaller errors than previous work in the literature, we obtain a clear trend of increasing $^{18}$O$/^{17}$O ratio with increasing galactocentric distance (D$_{GC}$), which provides a significant constraint on Galactic chemical evolution (GCE) models. Current GCE models have to be improved in order to explain the observed C$^{18}$O/C$^{17}$O 1-0 gradient.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2023-04-04T08:06:08.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "abundance ratio",
      "parallax distances",
      "fifty-one massive star forming regions",
      "simultaneous observations",
      "yebes 40m telescope"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 15,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}