Discovery of Tidal RR LYRAE stars in the Bulge Globular Cluster M 62
  The RR Lyrae (RRL) rich globular cluster M 62 (NGC 6266) is one of the most
massive globular clusters in the Milky Way, located in the dense region of the
Galactic bulge, where dynamical processes that affect the survival of globular
clusters are maximised. Using Gaia DR2 data we have found clear evidence for an
excess of RRLs beyond the cluster tidal radius of M 62, associated partly with
stars stripped into the Galaxy field. This is confirmed with new VVVX survey
observations, that discard any differential reddening effect as the possible
cause of the observed RRL density excess. We also determined the orbit of M 62
using accurate new measurements of its distance, radial velocity and proper
motions (PMs), finding that its orbit is prograde respect to the direction of
the Galactic rotation. Orbits are integrated in the non-axisymmetric galactic
model \texttt{GravPot16}, which includes the perturbations due to the central
Galactic bar. M 62 shows a particular orbital behaviour, having a dynamical
signature of the bar-bulge region. The small extra-tidal RRLs extensions
observed are roughly aligned towards the galactic center and the direction
almost perpendicular to the galactic plane and not with its motion along its
orbit, which may be a clear sign of bulge-crossing shocks, during the last
passage close of the cluster towards its perigalacticon. M 62 would be the
first clear observed case of bulge shocking in the inner Galaxy acting on a
globular cluster.
