LOW-MASS STAR-FORMATION IN COOLING FLOW GALAXIES

Observations are presented based on optical and near-IR imaging to sup port the idea that isolated and cluster cooling flow galaxies are enri ched in low-mass stars, the result of recent, truncated IMF star forma tion from accreting gas. Galaxies with low accretion rates (M < 5 M. y r-1) have normal optical colors and gradients, but red V - K colors si gnaling an IMF enhanced in low-mass main-sequence stars. Cluster cooli ng flow ellipticals (M > 50 M. yr-1) selected to have blue optical col ors indicative of recent star formation also show redder V-K colors wi th respect to expected values for a weak starburst. The strength of th e starburst in the U - V, V - K diagram indicates an efficiency which places only 5% of the accreting matter into an IMF similar to that fou nd in the Galactic disk and the remaining mass is again sited in low-m ass stars.