Models of class II methanol masers based on improved molecular data

Details Models of class II methanol masers based on improved molecular data Models of class II methanol masers based on improved molecular data

2005-04-08

arxiv.org/abs/astro-ph/0504194v1

Mon.Not.Roy.Astron.Soc. 360 (2005) 533-545

Astronomy and Astrophysics

Astrophysics

14 pages, 4 figures, Accepted for publication in MNRAS

Scientific paper

10.1111/j.1365-2966.2005.09077.x

The class II masers of methanol are associated with the early stages of formation of high-mass stars. Modelling of these dense, dusty environments has demonstrated that pumping by infrared radiation can account for the observed masers. Collisions with other molecules in the ambient gas also play a significant role, but have not been well modelled in the past. Here we examine the effects on the maser models of newly available collision rate coefficients for methanol. The new collision data does not alter which transitions become masers in the models, but does influence their brightness and the conditions under which they switch on and off. At gas temperatures above 100 K the effects are broadly consistent with a reduction in the overall collision cross-section. This means, for example, that a slightly higher gas density than identified previously can account for most of the observed masers in W3(OH). We have also examined the effects of including more excited state energy levels in the models, and find that these play a significant role only at dust temperatures above 300 K. An updated list of class II methanol maser candidates is presented.

Affiliated with

Also associated with

No associations

Rating

Models of class II methanol masers based on improved molecular data 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 Models of class II methanol masers based on improved molecular data, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Models of class II methanol masers based on improved molecular data will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-683650