{
  "id": "2203.12255",
  "version": "v1",
  "published": "2022-03-23T08:05:36.000Z",
  "updated": "2022-03-23T08:05:36.000Z",
  "title": "ATOMS: ALMA Three-millimeter Observations of Massive Star-forming regions - X. Chemical differentiation among the massive cores in G9.62+0.19",
  "authors": [
    "Y. P. Peng",
    "T. Liu",
    "S. -L. Qin",
    "T. Baug",
    "H. -L. Liu",
    "K. Wang",
    "G. Garay",
    "C. Zhang",
    "L. -F. Chen",
    "C. W. Lee",
    "M. Juvela",
    "D. L. Li",
    "K. Tatematsu",
    "X. -C. Liu",
    "J. -E. Lee",
    "G. Luo",
    "L. Dewangan",
    "Y. -F. Wu",
    "L. Zhang",
    "L. Bronfman",
    "J. X. Ge",
    "M. Y. Tang",
    "Y. Zhang",
    "F. -W. Xu",
    "Y. Wang",
    "B. Zhou"
  ],
  "comment": "40 pages, 23 figures",
  "categories": [
    "astro-ph.GA"
  ],
  "abstract": "Investigating the physical and chemical structures of massive star-forming regions is critical for understanding the formation and the early evolution of massive stars. We performed a detailed line survey toward six dense cores named as MM1, MM4, MM6, MM7, MM8, and MM11 in G9.62+0.19 star-forming region resolved in ALMA band 3 observations. Toward these cores, about 172 transitions have been identified and attributed to 16 species including organic Oxygen-, Nitrogen-, Sulfur-bearing molecules and their isotopologues. Four dense cores MM7, MM8, MM4, and MM11 are line rich sources. Modeling of these spectral lines reveals the rotational temperature in a range of 72$-$115~K, 100$-$163~K, 102$-$204~K, and 84$-$123~K for the MM7, MM8, MM4, and MM11, respectively. The molecular column densities are 1.6 $\\times$ 10$^{15}$ $-$ 9.2 $\\times$ 10$^{17}$~cm$^{-2}$ toward the four cores. The cores MM8 and MM4 show chemical difference between Oxygen- and Nitrogen-bearing species, i.e., MM4 is rich in oxygen-bearing molecules while nitrogen-bearing molecules especially vibrationally excited HC$_{3}$N lines are mainly observed in MM8. The distinct initial temperature at accretion phase may lead to this N/O differentiation. Through analyzing column densities and spatial distributions of O-bearing Complex Organic Molecules (COMs), we found that C$_{2}$H$_{5}$OH and CH$_{3}$OCH$_{3}$ might have a common precursor, CH$_{3}$OH. CH$_{3}$OCHO and CH$_{3}$OCH$_{3}$ are likely chemically linked. In addition, the observed variation in HC$_{3}$N and HC$_{5}$N emission may indicate that their different formation mechanism at hot and cold regions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2022-03-23T08:05:36.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "massive star-forming regions",
      "alma three-millimeter observations",
      "massive cores",
      "chemical differentiation",
      "dense cores"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 40,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}