  Within the context of ultralight BEC dark matter, we analyze the head-on
encounters of two structures. These structures are made of a BEC component,
which is a ground state equilibrium solution of the Gross-Pitaevskii-Poisson
system, together with a component of luminous matter. The evolution of the
Condensate dark matter is carried out by solving the time dependent GPP
equations, whereas the luminous matter is modeled with particles interacting
gravitationally on top of the BEC dark matter halos. We track the evolution of
frontal encounters for various values of the collision velocity and analyze the
regime of high velocity regime showing solitonic behavior of the BEC halos and
that of slow velocities producing a single final structure. We measure the
relative velocity of the dark matter with respect to the luminous matter after
the encounters in the solitonic case and track the evolution of luminous matter
in the case of merger.
