Methanol Masers: Reliable Tracers of the Early Stages of High-mass Star Formation
Ellingsen, S (2006) Methanol Masers: Reliable Tracers of the Early Stages of High-mass Star Formation. The Astrophysical Journal, 638 (1). pp. 241-261. ISSN 1538-4357
Official URL: http://dx.doi.org/10.1086/498673
The GLIMPSE and MSX surveys have been used to examine the mid-infrared properties of a statistically complete sample of 6.7 GHz methanol masers. The GLIMPSE point sources associated with methanol masers are clearly distinguished from the majority, typically having extremely red mid-infrared colors, similar to those expected of low-mass class 0 young stellar objects. The intensity of the GLIMPSE sources associated with methanol masers is typically 4 magnitudes brighter at 8.0 micron than at 3.6 micron.
Targeted searches towards GLIMPSE point sources with [3.6]-[4.5] > 1.3 and an 8.0 micron magnitude less than 10 will detect more than 80% of class II methanol masers. Many of the methanol masers are associated with sources within infrared dark clouds (IRDC) which are believed to mark regions where high-mass star formation is in its very early stages. The presence of class II methanol masers in a significant fraction of IRDC suggests that high-mass star formation is common in these regions. Different maser species are thought to trace different evolutionary phases of the high-mass star formation process. Comparison of the properties of the GLIMPSE sources associated with class II methanol masers and other maser species shows interesting trends, consistent with class I methanol masers tracing a generally earlier evolutionary phase and OH masers tracing a later evolutionary phase.
|Keywords:||star formation, masers, infrared, interstellar medium|
|Deposited By:||Dr Simon Ellingsen|
|Deposited On:||20 Dec 2006|
|Last Modified:||18 Jul 2008 19:45|
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