  Using parsec scale resolution hydrodynamical adaptive mesh refinement
simulations we have studied the mass transport process throughout a galactic
merger. The aim of such study is to connect both the peaks of mass accretion
rate onto the BHs and star formation bursts with both gravitational and
hydrodynamic torques acting on the galactic gaseous component. Our merger
initial conditions were chosen to mimic a realistic system.
  The simulations include gas cooling, star formation, supernovae feedback, and
AGN feedback. Gravitational and hydrodynamic torques near pericenter passes
trigger gas funneling to the nuclei which is associated with bursts of star
formation and black hole growth. Such episodes are intimately related with both
kinds of torques acting on the galactic gas. Pericenters trigger both star
formation and mass accretion rates of $\sim$ few $(1-10)$ $M_\odot$/yr. Such
episodes last $\sim$ $(50-75)$ Myrs. Close passes also can produce black hole
accretion that approaches and reaches the Eddington rate, lasting $\sim$ few
Myrs. Our simulation shows that both gravitational and hydrodynamic torques are
enhanced at pericenter passes with gravitational torques tending to have higher
values than the hydrodynamic torques throughout the merger. We also find that
in the closest encounters, hydrodynamic and gravitational torques can be
comparable in their effect on the gas, the two helping in the redistribution of
both angular momentum and mass in the galactic disc. Such phenomena allow
inward mass transport onto the BH influence radius, fueling the compact object
and lighting up the galactic nuclei.
