{
  "id": "2007.10426",
  "version": "v1",
  "published": "2020-07-20T19:32:44.000Z",
  "updated": "2020-07-20T19:32:44.000Z",
  "title": "Ultracompact HII regions with extended emission: The case of G43.89-0.78 and its molecular environment",
  "authors": [
    "Eduardo de la Fuente",
    "Daniel Tafoya",
    "Miguel A. Trinidad",
    "Alicia Porras",
    "Alberto Nigoche-Netro",
    "Simon N. Kemp",
    "Stanley E. Kurtz",
    "Jose Franco",
    "Carlos A. Rodriguez-Rico"
  ],
  "comment": "13 pages, 8 figures, 2 tables. Accepted for publication in the Monthly Notices of the Royal Astronomical Society Main Journal (2020)",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "The Karl Jansky Very Large Array (VLA), Owens Valley Radio Observatory (OVRO), Atacama Large Millimetric Array (ALMA), and the infrared \\textit{Spitzer} observatories, are powerful facilities to study massive star formation regions and related objects such as ultra--compact (UC) \\hii regions, molecular clumps, and cores. We used these telescopes to study the \\uchiir G43.89--0.78. The morphological study at arcminute scales using NVSS and \\textit{Spitzer} data shows that this region is similar to those observed in the \\textit{ bubble--like} structures revealed by \\textit{Spitzer} observations. With this result, and including a physical characterization based on 3.6 cm data, we suggest G43.89--0.78 be classified as an \\uchiir with Extended Emission because it meets the operational definition given in this paper comparing radio continuum data at 3.6 and 20~cm. For the ultra-compact component, we use VLA data to obtain physical parameters at 3.6~cm confirming this region as an \\uchii region. Using ALMA observations, we detect the presence of a dense ($2.6\\times10^7$ cm$^{-3}$) and small ($\\sim$ 2.0\\arcsec; 0.08 pc) molecular clump with a mass of 220 M$_{\\odot}$ and average kinetic temperature of 21~K, located near to the \\uchii region. In this clump, catalogued as G43.890--0.784, water masers also exist, possibly tracing a bipolar outflow. We discover in this vicinity two additional clumps which we label as G43.899--0.786 (T$_d$ = 50 K; M = 11 M$_{\\odot}$), and G43.888--0.787 (T$_d$ = 50 K; M = 15 M$_{\\odot}$).",
  "revisions": [
    {
      "version": "v1",
      "updated": "2020-07-20T19:32:44.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "ultracompact hii regions",
      "extended emission",
      "molecular environment",
      "owens valley radio observatory",
      "molecular clump"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 13,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}