Direct IR Determination of the Stellar Luminosity Function to 0.2 M_⊙ in Elliptical Galaxies

Summary

We present a determination of the stellar luminosity function in luminous elliptical galaxies which includes all stars more massive than 0.15 M_⊙. This limit corresponds to masses beyond the maximum in the solar neighbourhood stellar mass function, and therefore includes effectively all the luminous mass. Galaxies with X-ray evidence for current massive star formation, also show no evidence for enhanced low mass star formation in their central regions. All elliptical galaxies studied to date have stellar luminosity functions for masses above 0.15 solar masses which do not differ significantly from that in the solar neighbourhood. Elliptical galaxies have stellar bolometric mass-to-light ratios of 2.5< M/L <5.0.