The Initial Mass Function of Low‐Mass Stars and Brown Dwarfs in Taurus

By combining deep optical imaging and infrared spectroscopy with data fromthe Two-Micron All-Sky Survey (2MASS) and from previous studies (e.g., Bricenoet al.), I have measured the Initial Mass Function (IMF) for areddening-limited sample in four fields in the Taurus star forming region. ThisIMF is representative of the young populations within these fields for massesabove 0.02 Msun. Relative to the similarly derived IMF for the TrapeziumCluster (Luhman et al.), the IMF for Taurus exhibits a modest deficit of starsabove one solar mass (i.e., steeper slope), the same turnover mass (~0.8 Msun),and a significant deficit of brown dwarfs. If the IMF in Taurus were the sameas that in the Trapezium, 12.8+/-1.8 brown dwarfs (>0.02 Msun) are expected inthese Taurus fields where only one brown dwarf candidate is found. Theseresults are used to test theories of the IMF.