2015/03/31 by A. Sanna, K. M. Menten, C. Carrasco-González +6
Physics and Astronomy · Social Sciences · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Educational Leadership and Practices #Galaxy #Infrared #Maser #Megamaser #Protostar #Young stellar object #astro-ph.GA
paper · pdf · doi:10.1088/2041-8205/804/1/l2
12 pages, 3 figures, 2 tables, typos added, accepted by The Astrophysical Journal Letters
arxiv created 2015/04/14 · openalex publication_date 2015/04/23 · arxiv updated 2015/06/24 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
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 CH 3 OH, H 2 O, 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 CH 3 OH 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 CH 3 OH 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 CH 3 OH maser emission in the region of periodic variability.