The study of astrophysical masers is a very young branch of science, with a history extending back no further than the mid 1960s. Even so, the subject has advanced rapidly to the point where masers can be used as tools to investigate problems as diverse as the chemistry of comets and the measurement of the Hubble constant. Arecent (2007) international conference on astrophysical masers had over 120 delegates: hopefully this shows that the subject is as attractive to young astronomers today as it was to the pioneers who first detected these incredibly bright, and at the time mysterious, radio sources just 45 years ago.

The observational side of astrophysical maser research has always been a branch of radio astronomy, and developments in radio techniques continue to govern advances in the knowledge of masers. The inclusion of Chapter 4 is intended to provide the reader with sufficient knowledge of radio techniques to understand modern observing procedures. As most astrophysical masers originate from molecules, there is also a chapter (Chapter 5) devoted to molecular spectroscopy.

Intended readership

The book is aimed at senior undergraduates, postgraduate students and research workers in astronomy, but the first two chapters can be easily read by the non-specialist, as they contain little mathematics and technical detail. The same is true of Chapter 6, which takes a modern view of the main astrophysical environments in which masers form. Chapters 9 and 10, though more specialized, are also accessible to the reader who does not wish to delve into too much mathematical detail.