{
  "id": "1707.03963",
  "version": "v1",
  "published": "2017-07-13T02:36:24.000Z",
  "updated": "2017-07-13T02:36:24.000Z",
  "title": "MALT-45: A 7mm survey of the southern Galaxy - II. ATCA follow-up observations of 44GHz class I methanol masers",
  "authors": [
    "Christopher H. Jordan",
    "Andrew J. Walsh",
    "Shari L. Breen",
    "Simon P. Ellingsen",
    "Maxim A. Voronkov",
    "Lucas J. Hyland"
  ],
  "comment": "Accepted by MNRAS on 12 July 2017",
  "categories": [
    "astro-ph.GA",
    "astro-ph.SR"
  ],
  "abstract": "We detail interferometric observations of 44GHz class I methanol masers detected by MALT-45 (a 7mm unbiased auto-correlated spectral-line Galactic-plane survey) using the Australia Telescope Compact Array. We detect 238 maser spots across 77 maser sites. Using high-resolution positions, we compare the class I CH$_3$OH masers to other star formation maser species, including CS (1-0), SiO $v=0$ and the H53$\\alpha$ radio-recombination line. Comparison between the cross- and auto-correlated data has allowed us to also identify quasi-thermal emission in the 44GHz class I methanol maser line. We find that the majority of class I methanol masers have small spatial and velocity ranges ($<$0.5pc and $<$5 km s$^{-1}$), and closely trace the systemic velocities of associated clouds. Using 870$\\mu$m dust continuum emission from the ATLASGAL survey, we determine clump masses associated with class I masers, and find they are generally associated with clumps between 1000 and 3000 $M_\\odot$. For each class I methanol maser site, we use the presence of OH masers and radio recombination lines to identify relatively evolved regions of high-mass star formation; we find that maser sites without these associations have lower luminosities and preferentially appear toward dark infrared regions.",
  "revisions": [
    {
      "version": "v1",
      "updated": "2017-07-13T02:36:24.000Z"
    }
  ],
  "analyses": {
    "keywords": [
      "methanol maser",
      "atca follow-up observations",
      "44ghz class",
      "7mm survey",
      "southern galaxy"
    ],
    "note": {
      "typesetting": "TeX",
      "pages": 0,
      "language": "en",
      "license": "arXiv",
      "status": "editable"
    }
  }
}