Schedule by Session

Westerlund 1 is a young massive starburst cluster, with an age of approximately 5Myr and a current distance estimate of 5kpc. The cluster contains multiple RSGs, YHGs, OB supergiants and WR stars. As a cluster containing a diverse stellar population, it provides a significant opportunity to constrain mass-loss rates during the transitional phase of massive stellar evolution. Mass-loss rates are a fundamental property of stars, important for discovering the full picture of massive stellar evolution as well as information on stellar feedback to the surrounding ISM, and determining the eventual nature of the star’s death.
This talk will aim to discuss preliminary results from new high sensitivity wide bandwidth observations taken using the ATCA (Australian Telescope Compact Array). Observations were taken over two spectral bands, centred at 5.5 GHz and 9 GHz. Results will be presented for the population of stars, including detailed imaging of the extended nebulae surrounding the RSGs, the YHG 265, and the LBV 237, as well as the head of the cometary nebulae surrounding W20. Mass-loss rates derived from the images will aim to provide an insight into the structure of the stellar wind and associated clumping factors, especially when compared to observations taken of the cluster population at different wavelengths.