The Mass Dependence of Dwarf Satellite Galaxy Quenching
  We combine observations of the Local Group with data from the NASA-Sloan
Atlas to show the variation in the quenched fraction of satellite galaxies from
low mass dwarf spheroidals and dwarf irregulars to more massive dwarfs similar
to the Magellanic clouds. While almost all of the low mass ($M_\star \lesssim
10^7$ $M_\odot$) dwarfs are quenched, at higher masses the quenched fraction
decreases to approximately 40-50%. This change in the quenched fraction is
large, and suggests a sudden change in the effectiveness of quenching that
correlates with satellite mass. We combine this observation with models of
satellite infall and ram pressure stripping to show that the low mass
satellites must quench within 1-2 Gyr of pericenter passage to maintain a high
quenched fraction, but that many more massive dwarfs must continue to form
stars today even though they likely fell in to their host >5 Gyr ago. We also
characterize how the susceptibility of dwarfs to ram pressure must vary as a
function of mass if it is to account for the change in quenched fractions.
Though neither model predicts the quenching effectiveness a priori, this
modeling illustrates the physical requirements that the observed quenched
fractions place on possible quenching mechanisms.
