Coma Berenices: first evidence for incomplete vertical phase-mixing in
  local velocity space with RAVE - confirmed with Gaia DR2
  Before the publication of the Gaia DR2 we confirmed with RAVE and TGAS an
observation recently made with the GALAH survey by Quillen ey al. concerning
the Coma Berenices moving group in the Solar neighbourhood, namely that it is
only present at negative Galactic latitudes. This allowed us to show that it is
coherent in vertical velocity, providing a first evidence for incomplete
vertical phase-mixing. We estimated for the first time from dynamical arguments
that the moving group must have formed at most ~ 1.5 Gyr ago, and related this
to a pericentric passage of the Sagittarius dwarf satellite galaxy. The present
note is a rewritten version of the original arXiv post on this result now also
including a confirmation of our finding with Gaia DR2.
