The Environment of the Strongest Galactic Methanol Maser

Journal
Date Issued
2015
Author(s)
•
Menten, K. M.
•
Carrasco-González, C.
•
Reid, M. J.
•
Ellingsen, S. P.
•
Brunthaler, A.
•
•
•
Krishnan, V.
DOI
Description
Comments from an anonymous referee are gratefully acknowledged. This work has been supported by the ERC Advanced Grant GLOSTAR under grant agreement No. 247078. This work made use of the Swinburne University of Technology software correlator, developed as part of the Australian Major National Research Facilities Programme and operated under licence. The Australia Telescope Compact Array (/Parkes radio telescope/Mopra radio telescope/Long Baseline Array) is part of the Australia Telescope National Facility which is funded by the Commonwealth of Australia for operation as a National Facility managed by CSIRO. The VLBA and JVLA are operated by the National Radio Astronomy Observatory (NRAO). The NRAO is a facility of the National Science Foundation operated under cooperative agreement by Associated Universities, Inc.
Abstract
The high-mass star-forming site G009.62+00.20 E hosts the 6.7 GHz methanol maser source with the greatest flux density in the Galaxy which has been flaring periodically over the last 10 yr. We performed high-resolution astrometric measurements of the CH3OH, H2O, and OH maser emission and 7 mm continuum in the region. The radio continuum emission was resolved in two sources separated by 1300 AU. The CH3OH maser cloudlets are distributed along two north-south ridges of emission to the east and west of the strongest radio continuum component. This component likely pinpoints a massive young stellar object which heats up its dusty envelope, providing a constant IR pumping for the Class II CH3OH maser transitions. We suggest that the periodic maser activity may be accounted for by an independent, pulsating, IR radiation field provided by a bloated protostar in the vicinity of the brightest masers. We also report the discovery of an elliptical distribution of CH3OH maser emission in the region of periodic variability.
Volume
804
Issue
1
Start page
L2
Uri
Url
Issn Identifier
2041-8205
Ads BibCode
2015ApJ...804L...2S
Rights
open.access
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