Studying the effects of stellar feedback in RCW 49

Principal Investigator

Maitraiyee Tiwari

Proposal ID

09_0143

Category

ISM_AND_CIRCUMSTELLAR_MATTER

Keywords

• H II REGIONS
• MASSIVE STARS
• MOLECULAR CLOUDS
• MULTIWAVELENGTH STUDY

Abstract

The interaction of massive stars with their environment is a key driver of the evolution of the interstellar medium of galaxies both in the local universe as well as at high redshifts. With this proposal we wish to observe OI 63 and 145 μm lines toward RCW 49, which is one of the brightest massive star-forming regions in the southern Galaxy. With the available archival data of diffuse X-ray (Chandra), radio, IR (WISE, GLIMPSE, Spitzer and Herschel), sub millimeter (APEX) emission toward RCW 49, we aim to perform a comprehensive multiwavelength study to quantify the feedback in the RCW 49 HII region powered by the rich Westerlund 2 cluster. This study can also act as a template for future studies to understand stellar feedback in the Interstellar medium of the Milky Way and other galaxies. The major cooling lines of a PDR are the fine-structure lines of CII and OI observable in the far-IR. With the user ready CII data available in the SOFIA archive, we need the OI lines to complete our study of the PDR of RCW 49. Both 63 and 145 micron lines are important, the former being brighter but optically thick while the latter is mostly optically thin and is important for the interpretation of opacity effects. Analysis of these high resolution (spatially and spectrally) observations together with a comparison to theoretical photodissociation region (PDR) models, will allow us to probe gas temperature and density, and the FUV flux incident on the gas.