The extended halo of Centaurus A: uncovering satellites, streams, and
  substructures
  We present the widest-field resolved stellar map to date of the closest
($D\sim3.8$ Mpc) massive elliptical galaxy NGC 5128 (Centaurus A; Cen A),
extending out to a projected galactocentric radius of $\sim150$ kpc. The
dataset is part of our ongoing Panoramic Imaging Survey of Centaurus and
Sculptor (PISCeS) utilizing the Magellan/Megacam imager. We resolve a
population of old red giant branch stars down to $\sim1.5$ mag below the tip of
the red giant branch, reaching surface brightness limits as low as
$\mu_{V,0}\sim32$ mag arcsec$^{-2}$. The resulting spatial stellar density map
highlights a plethora of previously unknown streams, shells, and satellites,
including the first tidally disrupting dwarf around Cen A (CenA-MM-Dw3), which
underline its active accretion history. We report 13 previously unknown dwarf
satellite candidates, of which 9 are confirmed to be at the distance of Cen A
(the remaining 4 are not resolved into stars), with magnitudes in the range
$M_V=-7.2$ to $-13.0$, central surface brightness values of
$\mu_{V,0}=25.4-26.9$ mag arcsec$^{-2}$, and half-light radii of
$r_h=0.22-2.92$ kpc. These values are in line with Local Group dwarfs but also
lie at the faint/diffuse end of their distribution; interestingly, CenA-MM-Dw3
has similar properties to the recently discovered ultra-diffuse galaxies in
Virgo and Coma. Most of the new dwarfs are fainter than the previously known
Cen A satellites. The newly discovered dwarfs and halo substructures are
discussed in light of their stellar populations, and they are compared to those
discovered by the PAndAS survey of M31.
