The GIRAFFE Inner Bulge Survey (GIBS) III. Metallicity distributions and
  kinematics of 26 Galactic bulge fields
  Several recent studies have demonstrated that the Galactic bulge hosts two
components with different mean metallicities, and possibly different spatial
distribution and kinematics. As a consequence, both the metallicity
distribution and the radial velocity of bulge stars vary across different line
of sights. We present here the metallicity distribution function of red clump
stars in 26 fields spread across a wide area of the bulge, with special
emphasis on fields close to Galactic plane, at latitudes b=-2 and b=-1, that
were not explored before. This paper includes new metallicities from a sample
of about 5000 K giant stars, observed at spectral resolution R=6500, in the
Calcium II Triplet region. They are the main dataset of the GIRAFFE Inner Bulge
Survey. As part of the same survey we have previously published results for a
sample of about 600 K giant stars, at latitude b=-4 , derived from higher
resolution spectra (R=22,500). Results. The combined sample allows us to trace
and characterize the metal poor and metal rich bulge populations down to the
inner bulge. We present a density map for each of the two components. Contrary
to the expectations from previous works, we found the metal poor population to
be more centrally concentrated than the metal rich one, and with a more
axisymmetric spatial distribution. The metal rich population, on the other
hand, is arranged in a boxy distribution, consistent with an edge-on bar. By
coupling metallicities and radial velocities we show that the metal poor
population has a velocity dispersion that varies rather mildly with latitude.
On the contrary, the metal rich population has a low velocity dispersion far
from the plane (b=-8.5), but it has a steeper gradient with latitude, becoming
higher than the metal poor one in the innermost field (b=-1). [abridged]
