Prof Patrick Roche

Abstract:

The results of a search for OH megamaser emission from a sample of 32 galaxies selected from the IRAS Point Source Catalog on the basis of their IR properties are presented. For each galaxy (other than those few already observed elsewhere), an optical redshift is obtained and both OH and H I emission are sought. The search yielded one new OH megamaser galaxy, and H I was detected toward nine objects. There are unlikely to be any OH megamasers in the Southern Hemisphere with flux densities comparable to that of Arp 220 (280 mJy), although there may be a population of weaker megamasers. No special conditions are required to explain the known OH megamasers other than those expected in a cool, dusty, active galaxy.