The scaling relations of early-type dwarf galaxies across a range of
  environments
  We present the results of a Keck-ESI study of dwarf galaxies across a range
of environment: the Perseus Cluster, the Virgo Cluster, the NGC 1407 group, and
the NGC 1023 group. Eighteen dEs are targeted for spectroscopy, three for the
first time. We confirm cluster membership for one Virgo dE, and group
membership for one dE in the NGC 1023 group, and one dE in the NGC 1407 group
for the first time. Regardless of environment, the dEs follow the same
size-magnitude and $\sigma$-luminosity relation. Two of the Virgo dwarfs, VCC
1199 and VCC 1627, have among the highest central velocity dispersions
($\sigma_{0}$ = 58.4 km s$^{-1}$ and 49.2 km s$^{-1}$) measured for dwarfs of
their luminosity ($M_{R}\approx -17$). Given their small sizes ($R_{e} < 300$
pc) and large central velocity dispersions, we classify these two dwarfs as
compact ellipticals rather than dEs. Group dEs typically have higher mean
dynamical-to-stellar mass ratios than the cluster dEs, with $M_{dyn}/M_{\star}
= 5.1\pm0.6$ for the group dwarfs, vs. $M_{dyn}/M_{\star} = 2.2\pm0.5$ for the
cluster sample, which includes two cEs. We also search for trends in
$M_{dyn}/M_{\star}$ vs. distance from M87 for the Virgo Cluster population, and
find no preference for dwarfs with high values of $M_{dyn}/M_{\star}$ to reside
in the cluster outskirts vs. centre.
