This image is a near-infrared composite with wavelengths between 1.5 and 3.5 microns. The contours are of radio continuum emission. The cross shows the location of methanol masers, which provided a signpost that suggested the region was worth further study.

In 2005, I undertook a suite of millimetre-wave observations of the massive star forming region G305. I looked for a whole host of spectral lines in this region from molecules such as water, methanol, methyl cyanide, carbonyl sulfide, cyanoacetylene and ammonia. Measurement of thermal transitions confirm that G305A-A is a hot core and must be in a very early stage of star formation, with emission in molecules such as ammonia, methanol and cyanoacetylene. Furthermore, the methanol emission towards this object shows a prominent jet-like feature, which we interpret to be part of a bipolar jet expected from massive stars as they form, but rarely seen. For non-thermal lines, the observations turned up a strong water maser associated with G305-A, as well as weak class I methanol maser emission. The more developed region G305-B shows a very strong Class I methanol maser, which is unprecedented because the two class of methanol masers have not appeared this close together before.

I have been working with overseas collaborators on two other massive star forming regions: NGC6334 I and I(N). We discovered a large region of ammonia emission surrounding the source I(N), which has never been seen before. We intend to follow up this region this year with in-depth observations of the various chemical tracers that can be attained with the Mopra telescope. This will be a big step towards searching for a chemical clock that shows the signatures of the early stages of stellar evolution.

I have also been collaborating with researchers in the US on the low mass star forming region NGC 1333. Our work indicates that we can understand the formation of the initial mass function (IMF) better when in a clustered environment, such as NGC 1333. Preliminary results suggest that the IMF is locked in at a very early stage of evolution, much earlier than the formation of stars themselves.

Andrew Walsh