Stellar Content of the Galactic Starburst Template NGC 3603 from Adaptive Optics Observations

We present near-infrared adaptive optics imaging of the Galactic starburst template NGC 3603 and its stellar center HD 97950. There is clear evidence for the presence of stars down to one solar mass or less. No cutoff or turnover in the initial mass function is evident. Applying theoretical models of the pre-main-sequence evolution of intermediate mass stars to the observed color-color diagram, color-magnitude diagram and the luminosity function, we constrain both the age distribution and the initial mass function. Within the systematic errors, this initial mass function follows a Salpeter power law with index #GAMMA##<=#-0.73 down to the observational limit of less than one solar mass. The stars with less than four solar masses appear to be younger than one million years, in contrast to previous age determinations of the high mass content of HD 97950. (orig.)