STELLAR CONTENT OF THE GALACTIC STARBURST TEMPLATE NGC-3603 FROM ADAPTIVE OPTICS OBSERVATIONS

We present near-infrared adaptive optics imaging of the Galactic starb urst template NGC 3603 and its stellar center HD 97950. There is clear evidence for the presence of stars down to 1 M. or less. No cutoff or turnover in the initial mass function is evident. Applying theoretica l models of the pre-main-sequence evolution of intermediate-mass stars to the observed color-color diagram, the color-magnitude diagram, and the luminosity function, we constrain both the age distribution and t he initial mass function. Within the systematic errors, this initial m ass function follows a Salpeter power law with index Gamma less than o r equal to -0.73 down to the observational limit of less than 1 M. The stars with less than 4 M. appear to be younger than 10(6) yr, in cont rast to previous age determinations of the high-mass content of HD 979 50.