9417210 Wilking The study of the mass function of a young, embedded cluster of stars in the Galaxy is the most direct way to investigate the origin of stellar masses. The young stellar objects in molecular clouds in our Galaxy are strongly bound and have not had time to wander far from their birthplace. Interpretation of the observed peaks or low-mass cut-offs in the mass function of a young stellar cluster can reteal a possible characteristic or minimum mass for star formation which can be related to the local and global environment. However, infrared wavelength observations are needed to probe through the obscuring dust in these regions and new techniques must be developed to estimate stellar masses for pre-main-sequence stars from infrared data alone. Infrared wavelength array detectors will be used to observe a flux-limited sample of sources emitting at 2 micron wavelengths in the Rho Ophiuchi cloud core. A scheme will be devised to identify a subset of this sample which is in a T Tauri star type phase of evolution, for which the stellar photospheres can be corrected for obscuration effects, and using recent theoretical models for a given stellar age, the luminosities and masses of the stars can be derived. To supplement this observational sample of stars, new and sensitive X-ray, Hydrogen alpha, and radio wavelength continuum observational surveys will be used to identify young stars with little or no infrared excess. The goal is to produce a mass function for 100-150 young stellar objects in the cloud. As a check on the scheme that is planned, infrared wavelength spectroscopic observations of stars will be used to determine the spectral types of the stars and to independently estimate the ages and masses of the starq. In the course of the investigations, other important issues concerning the Rho Ophiuchi cloud core will be considered; such as the number of low-luminosity embedded sources, the three-dimensional distribution of young stars, the freque ncy of binary stars, and the degree of Hydrogen alpha wavelength emission variability in pre-main-sequence stars. Ultimately, the mass functions of several star-forming regions with distinct physical environments will be compared to see if significant differences do arise when comparing the different star forming regions.
