The Gaia-ESO survey: Metal-rich bananas in the bulge
  We analyse the kinematics of $\sim 2000$ giant stars in the direction of the
Galactic bulge, extracted from the Gaia-ESO survey in the region $-10^\circ
\lesssim \ell \lesssim 10^\circ$ and $-11^\circ \lesssim b \lesssim -3^\circ$.
We find distinct kinematic trends in the metal rich ($\mathrm{[M/H]}>0$) and
metal poor ($\mathrm{[M/H]}<0$) stars in the data. The velocity dispersion of
the metal-rich stars drops steeply with latitude, compared to a flat profile in
the metal-poor stars, as has been seen previously. We argue that the metal-rich
stars in this region are mostly on orbits that support the boxy-peanut shape of
the bulge, which naturally explains the drop in their velocity dispersion
profile with latitude. The metal rich stars also exhibit peaky features in
their line-of-sight velocity histograms, particularly along the minor axis of
the bulge. We propose that these features are due to stars on resonant orbits
supporting the boxy-peanut bulge. This conjecture is strengthened through the
comparison of the minor axis data with the velocity histograms of resonant
orbits generated in simulations of buckled bars. The 'banana' or 2:1:2 orbits
provide strongly bimodal histograms with narrow velocity peaks that resemble
the Gaia-ESO metal-rich data.
