Signatures of the Galactic bar on stellar kinematics unveiled by APOGEE
  Bars are common galactic structures in the local universe that play an
important role in the secular evolution of galaxies, including the Milky Way.
In particular, the velocity distribution of individual stars in our galaxy is
useful to shed light on stellar dynamics, and provides information
complementary to that inferred from the integrated light of external galaxies.
However, since a wide variety of models reproduce the distribution of velocity
and the velocity dispersion observed in the Milky Way, we look for signatures
of the bar on higher-order moments of the line-of-sight velocity ($V_{los}$)
distribution. We make use of two different numerical simulations --one that has
developed a bar and one that remains nearly axisymmetric-- to compare them with
observations in the latest APOGEE data release (SDSS DR14). This comparison
reveals three interesting structures that support the notion that the Milky Way
is a barred galaxy. A high skewness region found at positive longitudes
constrains the orientation angle of the bar, and is incompatible with the
orientation of the bar at $\ell=0^\circ$ proposed in previous studies. We also
analyse the $V_{los}$ distributions in three regions, and introduce the
Hellinger distance to quantify the differences among them. Our results show a
strong non-Gaussian distribution both in the data and in the barred model,
confirming the qualitative conclusions drawn from the velocity maps. In
contrast to earlier work, we conclude it is possible to infer the presence of
the bar from the kurtosis distribution.
