Cartography of Triangulum-Andromeda using SDSS stars
  The outer Galactic halo is home to a number of substructures which still have
an uncertain origin, but most likely are remnants of former interactions
between the Galaxy and its former satellites. Triangulum-Andromeda (TriAnd) is
one of these halo substructures, found as an overdensity of 2MASS M giants. We
analyzed the region of Triangulum-Andromeda using photometric data from the
Ninth Data Release of Sloan Digital Sky Survey (SDSS DR9). By comparing the
observations with simulations from the TRILEGAL Galactic model, we were able to
identify and map several scattered overdensities of main sequence stars that
seem to be associated with TriAnd over a large area covering $\sim 500$
deg$^2$. One of these excesses may represent a new stellar overdensity. We also
briefly discuss an alternative hypothesis, according to which TriAnd is one of
the troughs of oscillation rings in the Galactic disk.
