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This is the fourth and final instalment of a series of catalogues presenting 12.2-GHz methanol maser observations made towards each of the 6.7-GHz methanol masers detected in the Methanol Multibeam (MMB) survey. This final portion of the survey covers the 20°–60° longitude range, increasing the 12.2-GHz follow-up range to the full MMB coverage of 186° ≥ l ≤ 60° and |b| ≤ 2°. Towards a total of 260 6.7-GHz MMB methanol masers (we were unable to observe five of the MMB sources in this longitude range) we detect 116 12.2-GHz masers counterparts, 64 of which were discovered in this survey. Including data from the literature, we find that there are 12.2-GHz methanol masers towards 47.1 per cent of the 6.7-GHz methanol masers in this portion of the Galaxy. Across the entire MMB survey range, we find a detection rate of 45.3 per cent. We find that the detection rate of 12.2-GHz methanol masers as a function of Galactic longitude is not uniform and there is an excess of masers with broad velocity ranges at longitudes near 30° and 330°. Comparing the occurrence of 12.2-GHz methanol masers with MMB-targeted CO observations has shown that those outflows associated with a 12.2-GHz source have a larger average dynamical time-scale than those associated with only 6.7-GHz methanol masers, supporting the notion that the 12.2-GHz masers are associated with a later phase of high-mass star formation.

Item Type:	Refereed Article
Keywords:	masers–stars: formation–ISM: molecules–radiolines: ISM
Research Division:	Physical Sciences
Research Group:	Astronomical and Space Sciences
Research Field:	Galactic Astronomy
Objective Division:	Expanding Knowledge
Objective Group:	Expanding Knowledge
Objective Field:	Expanding Knowledge in the Physical Sciences
Author:	Ellingsen, SP (Professor Simon Ellingsen)
ID Code:	109829
Year Published:	2016
Deposited By:	Mathematics and Physics
Deposited On:	2016-07-04
Last Modified:	2017-01-30
Downloads:	35 View Download Statistics