{
  "id": "1912.08958",
  "version": "v1",
  "published": "2019-12-19T00:25:46.000Z",
  "updated": "2019-12-19T00:25:46.000Z",
  "title": "Ultracompact H II Regions with Extended Emission: The Complete View",
  "authors": [
    "Eduardo de la Fuente",
    "Alicia Porras",
    "Miguel A. Trinidad",
    "Stanley E. Kurtz",
    "Simon N. Kemp",
    "Daniel Tafoya",
    "José Franco",
    "Carlos Rodríguez-Rico"
  ],
  "comment": "21 pages, 4 figures, to be Published on Monthly Notices of the Royal Astronomical Society (Accepted: December, 18, 2019)",
  "doi": "10.1093/mnras/stz3482",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "In this paper we present the results of a morphological study performed on a sample of 28 ultracompact \\hiirs~located near extended free-free emission, using radio continuum observations at 3.6~cm with the C and D VLA~configurations, with the aim of determining a direct connection between them. By using previously published observations in B and D VLA~configurations, we compiled a final catalogue of 21 ultracompact \\hiirs ~directly connected with the surrounding extended emission. The observed morphology of most of the ultracompact \\hiirs~in radio continuum emission is irregular (single or multi-peaked sources) and resembles a classical bubble structure in the Galactic plane with well-defined cometary arcs. Radio continuum images superimposed on colour composite \\textit{Spitzer} images reinforce the assignations of direct connection by the spatial coincidence between the ultracompact components and regions of saturated 24~\\micron~emission. We also find that the presence of extended emission may be crucial to understand the observed infrared-excess because an underestimation of ionizing Lyman photons was considered in previous works.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2019-12-19T00:25:46.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "extended emission",
      "ultracompact",
      "complete view",
      "direct connection",
      "radio continuum images"
    ],
    "tags": [
      "journal article"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 21,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}