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The environment of the strongest galactic methanol maser
journal contributionposted on 2023-05-18, 09:38 authored by Sanna, A, Menten, KM, Carrasco-Gonzalez, C, Reid, MJ, Simon EllingsenSimon Ellingsen, Brunthaler, A, Moscadelli, L, Cesaroni, R, Krishnan, V
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.
Publication titleThe Astrophysical Journal Letters
Department/SchoolSchool of Natural Sciences
PublisherInstitute of Physics Publishing Ltd.
Place of publicationUnited Kingdom
Rights statementCopyright 2015. The American Astronomical Society.