How do methanol masers manage to appear in the youngest star vicinities and isolated molecular clumps?

Details How do methanol masers manage to appear in the youngest star vicinities and isolated molecular clumps? How do methanol masers manage to appear in the youngest star vicinities and isolated molecular clumps?

2007-06-21

arxiv.org/abs/0706.3117v1

Astronomy and Astrophysics

Astrophysics

8 pages, 4 figures, invited presentation at IAU242 "Astrophysical Masers and their environments"

Scientific paper

10.1017/S1743921307012616

General characteristics of methanol (CH3OH) maser emission are summarized. It is shown that methanol maser sources are concentrated in the spiral arms. Most of the methanol maser sources from the Perseus arm are associated with embedded stellar clusters and a considerable portion is situated close to compact HII regions. Almost 1/3 of the Perseus Arm sources lie at the edges of optically identified HII regions which means that massive star formation in the Perseus Arm is to a great extent triggered by local phenomena. A multiline analysis of the methanol masers allows us to determine the physical parameters in the regions of maser formation. Maser modelling shows that class II methanol masers can be pumped by the radiation of the warm dust as well as by free-free emission of a hypercompact region hcHII with a turnover frequency exceeding 100 GHz. Methanol masers of both classes can reside in the vicinity of hcHIIs. Modelling shows that periodic changes of maser fluxes can be reproduced by variations of the dust temperature by a few percent which may be caused by variations in the brightness of the central young stellar object reflecting the character of the accretion process. Sensitive observations have shown that the masers with low flux densities can still have considerable amplification factors. The analysis of class I maser surveys allows us to identify four distinct regimes that differ by the series of their brightest lines.

Affiliated with

Also associated with

No associations

Rating

How do methanol masers manage to appear in the youngest star vicinities and isolated molecular clumps? does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with How do methanol masers manage to appear in the youngest star vicinities and isolated molecular clumps?, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and How do methanol masers manage to appear in the youngest star vicinities and isolated molecular clumps? will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-192549