Resolving the extended stellar halos of nearby galaxies: the wide-field
  PISCeS survey
  In the wide-field Panoramic Imaging Survey of Centaurus and Sculptor
(PISCeS), we investigate the resolved stellar halos of two nearby galaxies (the
elliptical Centaurus A and the spiral Sculptor, D $\sim3.7$ Mpc) out to a
projected galactocentric radius of 150 kpc with Magellan/Megacam. The survey
has led to the discovery of $\sim$20 faint satellites to date, plus prominent
streams and substructures in two environments that are substantially different
from the Local Group, i.e. the Centaurus A group dominated by an elliptical and
the loose Sculptor group of galaxies. These discoveries clearly attest to the
importance of past and ongoing accretion processes in shaping the halos of
these nearby galaxies, and provide the first census of their satellite systems
down to an unprecedented $M_V<-8$. The detailed characterization of the stellar
content, shape and gradients in the extended halos of Sculptor, Centaurus A,
and their dwarf satellites provides key constraints on theoretical models of
galaxy formation and evolution.
