GBT25B-320

Neglected Class II Methanol Masers

Abstract

Methanol masers are widespread in the Galaxy, with over 1200 currently
reported. The most common and brightest of these is the
6.7 GHz class II maser, pumped by the infrared radiation of
young, massive stars. This maser, and its companion at 12.2 GHz,
have been extensively surveyed and numerous catalogs exist.

Other methanol maser lines are much less common.
The reason for this is not clear, although it is
suggested that the physical conditions giving rise to these 'rare'
transitions may be uncommon or short-lived. To test this conjecture,
restrictions on maser models are required, and fundamental to this is
to measure the relative intensity of distinct maser transitions.

The class II Ka-band lines at 37.70, 38.29 and 38.45 GHz are a set of
transitions that have been little-studied compared to the more common
6.7 and 12.2 GHz lines: a single survey covering the southern and
northern hemispheres (with Mopra and Onsala) has been published.

We propose a survey that will be much more sensitive than the existing
survey, and should provide useful data to further model class II
masers, and shed light on their rarity with respect to the 6.7 and
12.2 GHz lines.

Investigators

Name	Institution
Jetzael Cuazoson *	Instituto de Radioastronomia y Astrofisica
Stan Kurtz	México, Universidad Nacional Autónoma de

* indicates the PI