Appearances can be deceiving: clear signs of accretion in the seemingly
  ordinary Sextans dSph
  We report the discovery of clear observational signs of past accretion/merger
events in one of the Milky Way satellite galaxies, the Sextans dwarf spheroidal
(dSph). These were uncovered in the spatial distribution, internal kinematics
and metallicity properties of Sextans stars using literature CTIO/DECam
photometric and Magellan/MMFS spectroscopic catalogues. We find the spatial
distribution of stars to vary as a function of the colour/metallicity, being
rather regular and round for the blue (metal-poor) red giant branch and
main-sequence turn-off stars but much more elliptical and irregularly shaped
for the red (metal-rich) ones, with a distinct "shell-like" overdensity in the
northeast side. We also detect kinematic anomalies, in the form of a
"ring-like" feature with a considerably larger systemic line-of-sight velocity
and lower metallicity than the rest of stars; even the photometrically selected
component with a regular looking spatial distribution displays complex
kinematics. With a stellar mass of just $\sim5\times10^{5} M_{\odot}$, Sextans
becomes the smallest galaxy presenting clear observational signs of accretion
to date.
