No CrossRef data available.
Published online by Cambridge University Press: 14 August 2015
The velocity structure of OH profiles of OH maser regions is used to estimate the time scales of the source distributions. Time scales are found to be of the order of a few thousand years in typical cases. The velocity dispersions and intensity distribution of components are interpreted in terms of a collapsing cloud model of the emission regions. The masses of the clouds are found to be in the range from a few solar masses to a few hundred solar masses for the well-known emission regions.