Discovery of the new class I methanol maser transition at 23.4 GHz

  title={Discovery of the new class I methanol maser transition at 23.4 GHz},
  author={Maxim A. Voronkov and Andrew J. Walsh and James L. Caswell and Simon P. Ellingsen and Shari L. Breen and Steven N. Longmore and Cormac R. Purcell and James S. Urquhart},
  journal={Monthly Notices of the Royal Astronomical Society},
We report the first detection of a methanol maser in the 101–92 A− transition at 23.4 GHz, discovered during the H2O southern Galactic Plane Survey (HOPS) with the 22-m Mopra Radio Telescope. In the region covered by HOPS, the 23.4-GHz maser was found at only one location, G357.97−0.16, which was also a prominent source of maser emission in the J2–J1 E series near 25 GHz. The Australia Telescope Compact Array (ATCA) was used to followup these detections at high angular resolution and prove… 

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