Revealing the Embedded Structures and Sourcess within Giant HII Regions: The Northern Hemisphere Sample

Principal Investigator

James De Buizer

Proposal ID

04_0001

Category

ISM AND CIRCUMSTELLAR MATTER

Keywords

• DUST
• H II REGIONS
• IMAGING
• STAR FORMATION
• YOUNG STARS AND PROTOSTELLAR OBJECTS

Abstract

Most studies concentrate on the processes of isolated low-mass star formation while little is known about massive star formation and clustered star formation, despite the fact that the vast majority of stars are formed within OB clusters. Giant HII regions harbor the most active areas of OB star formation in the Galaxy, and as such are fantastic laboratories for the study of massive star formation as well as clustered star formation. However, most of these GHII regions are optically obscured and far away, requiring them to be studied in the MIR/FIR with adequate spatial resolution. SOFIA 19.7 and 37.1um imaging with approximately 3 arcsecond resolution is well-suited for revealing the embedded structures and sources within these regions. These SOFIA observations will be combined with data taken at other wavelengths to quantify the detailed physical properties within GHII regions individually and as a population. The observations will also expose the areas of the youngest stages of massive star formation within the GHII regions and allow for the confirmation or confrontation of the recently proposed evolutionary sequence of GHII regions. This proposal is designed to catalog all of the known GHII regions at the highest spatial resolutions yet achievable at IR wavelengths greater than 20um. GHII regions are a dominant source of emission contributing to the bolometric luminosity that we see from galaxies in general. Therefore, understanding the global and detailed properties of GHII regions in our own Galaxy can be used as a template for interpreting what we observe in galaxies far away.