PI: Morten Andersen, California Institute of Technology, firstname.lastname@example.org
Address: Spitzer Science Center, 1200 E california blvd, MS 220-6, pasadena, ca 91125, usa
CoI: Hwankyung Sung, California Institute of Technology
CoI: Jeonghee Rho, California Institute of Technology
Title: Optical spectroscopy of candidate pre-main sequence stars in the Trifid Nebula : Disk properties in a massive star-forming environment
Abstract: The formation and evolution of circumstellar disks is an important component in star and planet formation models. Although the early evolution of circumstellar disks has been characterised in nearby cluster (Haisch et al. 2001), little is know about the disk fraction in young massive regions. Here we propose deep optical spectroscopy of some 320 young (0.3 Myr) stellar objects in the Trifid Nebula identified in \it Spitzer and \it Chandra images. We further propose deep optical imaging to search for the optical counterparts of the X-ray and mid-infrared sources. Our goals which require intermediate resolution spectroscopy include: i) determine the effective temperature for these objects and thus be able to place in them in the HR diagram and determine the age and mass of each star; ii) Combine the long wavelength \it Spitzer data with the age and mass for each star to examine disk properties, such as the disk frequency settling, truncated outer disks, or inner holes, in the environment of a young HII region; and iii) to determine the nature of `hot excess' stars identified in the \it Spitzer IRAC and MIPS bands.
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