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A search for water masers associated with class II methanol masers – I. Longitude range 6°–20°
journal contribution
posted on 2023-05-18, 02:33 authored by Titmarsh, AM, Simon EllingsenSimon Ellingsen, Breen, SL, Caswell, JL, Voronkov, MAThe Australia Telescope Compact Array has been used to search for 22-GHz water masers towards the 119 6.7-GHz methanol masers detected in the Methanol MultiBeam survey between Galactic longitudes 6° and 20°; we find water masers associated with 55 (~46 per cent). Methanol masers with associated water masers have a higher mean integrated luminosity than those without and there is a general trend for sources with more luminous 6.7-GHz methanol masers to be associated with more luminous water maser emission. We have inspected the GLIMPSE (Galactic Legacy Infrared Mid-plane Survey Extraordinaire) three colour images of the regions surrounding the masers and cross-matched the maser positions with existing catalogues of Extended Green Objects and infrared dark clouds. We find more Extended Green Objects at sites where both methanol and water masers are present than at sites with only methanol masers, but no significant difference in the fraction embedded within infrared dark clouds. Analysis of the 1.1-mm dust emission shows dust clumps associated with masers that have greater flux densities and higher column densities than those without. Dust clumps associated with both water and 6.7-GHz methanol masers are generally the most compact clumps followed by those associated with only methanol then the clumps without associated maser emission. We conclude that protostars with both methanol and water masers are often older than those with only methanol; however, we suggest that the evolutionary phase traced by water masers is not as well defined as for 6.7-GHz methanol masers.
History
Publication title
Monthly Notices of the Royal Astronomical SocietyVolume
443Issue
4Pagination
2923-2939ISSN
0035-8711Department/School
School of Natural SciencesPublisher
Blackwell Publishing LtdPlace of publication
9600 Garsington Rd, Oxford, England, Oxon, Ox4 2DgRights statement
Copyright 2014 The AuthorsRepository Status
- Restricted