Exoplanets in the Galactic context: Planet occurrence rates in the thin
  disk, thick disk and stellar halo of Kepler stars
  In order to gain a better understanding of planet formation and evolution, it
is important to examine the statistics of exoplanets in the Galactic context.
By combining information on stellar elemental abundances and kinematics, we
constructed separate samples of Kepler stars according to their affiliation to
the Galactic components of thin disk, thick disk and stellar halo. Using a
Bayesian analysis with conjugate priors, we then investigated how planet
occurrence rates differ in different regions of planet properties. We find that
young, slow and metal-rich stars, associated mainly with the thin disk, host on
average more planets (especially close-in super Earths) compared to the old,
fast and metal-poor thick disk stars. We further assess the dependence between
stellar properties such as spectral type and metallicity, and planet occurrence
rates. The trends we find agree with those found by other authors as well. We
argue that in the Galactic context, these are probably not the main properties
that affect planet occurrence rates, but rather the dynamical history of stars,
and especially stellar age and kinematics, impact the current distribution of
planets in the Galaxy.
