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Detection of 36GHz Class I methanol maser emission toward NGC 4945
journal contribution
posted on 2023-05-19, 11:11 authored by Tiege McCarthyTiege McCarthy, Simon EllingsenSimon Ellingsen, Chen, X, Breen, SL, Voronkov, MA, Qiao, H-hWe have searched for emission from the 36.2 GHz (4-1 → 30E) methanol transition toward NGC 4945, using the Australia Telescope Compact Array. 36.2 GHz methanol emission was detected offset southeast from the Galactic nucleus. The methanol emission is narrow, with a line width <10 km s−1 and a luminosity five orders of magnitude higher than Galactic class I masers from the same transition. These characteristics combined the with physical separation from the strong central thermal emission suggests that the methanol emission is a maser. This emission is a factor of ∼90 more luminous than the widespread emission detected from the Milky Way central molecular zone. This is the fourth detection of extragalactic class I emission and the third detection of extragalactic 36.2 GHz maser emission. These extragalactic class I methanol masers do not appear to be simply highly luminous variants of Galactic class I emission and instead appear to trace large-scale regions of low-velocity shocks in molecular gas, which may precede, or be associated with, the early stages of large-scale star formation.
History
Publication title
Astrophysical JournalVolume
846Article number
156Number
156Pagination
1-5ISSN
0004-637XDepartment/School
School of Natural SciencesPublisher
Univ Chicago PressPlace of publication
1427 E 60Th St, Chicago, USA, Il, 60637-2954Rights statement
Copyright 2017 The American Astronomical SocietyRepository Status
- Open