A2A: 21,000 bulge stars from the ARGOS survey with stellar parameters on
  the APOGEE scale
  We use the data-driven method, The Cannon, to bring 21,000 stars from the
ARGOS bulge survey, including 10,000 red clump stars, onto the parameter and
abundance scales of the cross-Galactic survey, APOGEE, obtaining rms precisions
of 0.10 dex, 0.07 dex, 74 K, and 0.18 dex for [Fe/H], [Mg/Fe], Teff, and
log(g), respectively. The re-calibrated ARGOS survey - which we refer to as the
A2A survey - is combined with the APOGEE survey to investigate the abundance
structure of the Galactic bulge. We find X-shaped [Fe/H] and [Mg/Fe]
distributions in the bulge that are more pinched than the bulge density, a
signature of its disk origin. The mean abundance along the major axis of the
bar varies such that the stars are more [Fe/H]-poor and [Mg/Fe]-rich near the
Galactic center than in the long bar/outer bulge region. The vertical [Fe/H]
and [Mg/Fe] gradients vary between the inner bulge and long bar with the inner
bulge showing a flattening near the plane that is absent in the long bar. The
[Fe/H]-[Mg/Fe] distribution shows two main maxima, an ``[Fe/H]-poor [Mg/Fe]-
rich'' maximum and an ``[Fe/H]-rich [Mg/Fe]-poor'' maximum, that vary in
strength with position in the bulge. In particular, the outer long bar close to
the Galactic plane is dominated by super-solar [Fe/H], [Mg/Fe]-normal stars.
Stars composing the [Fe/H]-rich maximum show little kinematic dependence on
[Fe/H], but for lower [Fe/H] the rotation and dispersion of the bulge increase
slowly. Stars with [Fe/H]<-1 dex have a very different kinematic structure than
stars with higher [Fe/H]. Comparing with recent models for the Galactic
boxy-peanut bulge, the abundance gradients and distribution, and the relation
between [Fe/H] and kinematics suggest that the stars comprising each maximum
have separate disk origins with the ``[Fe/H]-poor [Mg/Fe]-rich'' stars
originating from a thicker disk than the ``[Fe/H]-rich [Mg/Fe]-poor'' stars.
