The structure of Andromeda II dwarf spheroidal galaxy
  We analyze in detail the spatial distribution and kinematic properties of two
different stellar populations in Andromeda II (And II) dwarf spheroidal galaxy.
We obtained their detailed surface density maps, together with their radial
density profiles. The two populations differ not only in age and metallicity,
but also in their spatial distribution and kinematics. Old stars ($\gtrsim 11$
Gyr) follow a round distribution well fitted by truncated density profiles.
These stars rotate around the projected optical major axis of the galaxy with
line-of-sight velocities $v_{los}(r_h) = 16 \pm 3$ km s$^{-1}$ and a velocity
gradient of $2.06 \pm 0.21$ km s$^{-1}$ arcmin$^{-1}$. Intermediate-age stars
($\lesssim 9$ Gyr) concentrate in the centre of the galaxy and form an
elongated structure extending along the projected optical major axis. This
structure appears to rotate with a velocity gradient of $2.24 \pm 0.22$ km
s$^{-1}$ arcmin$^{-1}$, and around the optical minor axis. The centres of
rotation and kinetic position angles (PA$_{\rm kin}$) of both populations
differ. For intermediate-age stars we obtained PA$_{\rm kin} = 18^\circ \pm
2^\circ$ and for the old ones PA$_{\rm kin} = 63^\circ \pm 3^\circ$ in good
agreement with photometric PA measured from isopleths fitted to the photometry.
We conclude that the two stellar populations may not be fully relaxed and thus
be the result of a merger occurred at redshift $z\sim 1.75$.
