Dynamical Masses for a Complete Census of Local Dwarf Galaxies

Joshua D. Simon, Keith Bechtol, Alex Drlica-Wagner, Marla Geha, Vera Gluscevic, Alex Ji, Evan Kirby, Ting S. Li, Ethan O. Nadler, Andrew B. Pace, Annika Peter, Risa Wechsler

Published 2019-03-12Version 1

The 2020s are poised to continue the past two decades of significant advances based on observations of dwarf galaxies in the nearby universe. Upcoming wide-field photometric surveys will probe substantially deeper than previous data sets, pushing the discovery frontier for new dwarf galaxies to fainter magnitudes, lower surface brightnesses, and larger distances. These dwarfs will be compelling targets for testing models of galaxy formation and cosmology, including the properties of dark matter and possible modifications to gravity. However, most of the science that can be extracted from nearby dwarf galaxies relies on spectroscopy with large telescopes. We suggest that maximizing the scientific impact of near-future imaging surveys will require both major spectroscopic surveys on 6-10m telescopes and multiplexed spectroscopy with even larger apertures.