Program: GS-2007A-Q-60
| Title: | Silicate Optical Depth for a Complete Sample of Massive Young Stellar Objects |
| PI: | Joseph C. Mottram |
| Co-I(s): | Melvin Hoare, Stuart Lumsden, Andrew Clarke, Rene Oudmaijer |
Abstract
The Red MSX Source Survey will return an unbiased sample of ~500 massive young stellar objects (MYSOs) in our Galaxy. We propose to use 10 micron spectroscopy to begin measuring the line-of-sight (LOS) extinction to this sample. The LOS extinction is needed in order to deredden 1-5 micron emission lines that are diagnostics of the accretion disk and ionised stellar winds, and to normalise the strength of solid and gas phase absorption lines that trace chemical evolution. Modelling of the 9.7 micron silicate feature, together with the whole SED and clues to the inclination angle from other data will yield the true degree of embeddedness. This must somehow mark the evolutionary sequence in massive star formation.