PI: Jennifer Andrews, University of Massachusetts, firstname.lastname@example.org
Address: Astronomy Department, 710 North Pleasant Street, Amherst, MA 01003, USA
CoI: Daniela Calzetti, University of Massachusetts
CoI: Jay Gallagher, University of Wisconsin
CoI: Hwihyun Kim, Arizona State University
CoI: Rene Walterbos, New Mexico State University
CoI: Janice Lee, STScI
CoI: Jenna Ryon, University of Wisconsin
CoI: Sean McElwee, University of Massachusetts
Title: The Stellar Initial Mass Function: Universal or Not?
Abstract: Dwarf galaxies are sensitive laboratories for testing theories of star formation, and for investigating possible variations of the stellar Initial Mass Function. Establishing whether the IMF, in particular the upper end of the IMF (uIMF), is invariant or dependent upon the conditions of star formation is key for interpreting the vast majority of observations on galaxy evolution, and for understanding cosmic reionization. We propose to obtain narrow-band H(beta) imaging of 24 gas-rich, star-forming nearby dwarfs which are part of the sample from the recently approved Cycle 21 HST Treasury program LEGUS (Legacy ExtraGalactic UV Survey) to provide extinction measurements of the ionized gas. Complemented by the stellar clusters identified through the HST observations, these data will be essential to providing a definitive test of recent claims that the uIMF in dwarfs may be at variance with that of massive galaxies. We will also place limits on the leakage of ionizing photons from dwarfs.
National Optical Astronomy Observatory, 950 North Cherry Avenue, P.O. Box 26732, Tucson, Arizona 85726, Phone: (520) 318-8000, Fax: (520) 318-8360