Speaker????Dr. Simon Ellingsen

Affiliation: University of Tasmania, Australia

Title: Masers - Evolutionary clocks for high-mass star formation?

Time: Nov. 27th (Thursday), 14:00PM

Location: middle conf. room, 3rd floor

Abstract:

Interstellar masers are one of the best, if not the best signpost of young high-mass star formation regions. They are relatively common, intense and because they arise at centimetre wavelengths, are not affected by the high extinction that plagues observations in other wavelength ranges. Although progress has been slow towards the important goal of utilizing masers as tools to probe the details of star formation, the pace of advance has recently accelerated. The proliferation of complementary high-resolution observations of star formation regions at millimetre through mid-infrared wavelengths means that this trend is likely to continue.

The presence of an interstellar maser within a star formation region signifies ``special'' physical conditions. They are special in the sense that masing is only predicted to occur for certain ranges of temperature, density, molecular abundance etc. At present there remains significant uncertainty about where within star formation regions the different maser species arise and the evolutionary phase they are associated with. However, as relatively easily observed signposts of star formation regions, it would be very desirable to be able to use the presence or absence of the different maser species as an evolutionary clock. I will outline recent progress towards the goal of determining an evolutionary sequence for the common maser species. Focussing in particular on studies of the mid-infrared sources associated with the masers, and ATCA observations which are clarifying our understanding of the relationship between the two classes of methanol maser. I will also give a brief overview of current and future astronomical facilities at the University of Tasmania and the possibilities forfuture collaboration with telescopes in China and the the East-Asian region in general.