  The highest LHC energies give rise to production of many pairs of hard
partons which deposit four-momentum into the expanding fireball matter. We
argue that it is necessary to include momentum deposition during fireball
evolution into 3+1 dimensional hydrodynamic simulations of the collision. This
influence cannot be accounted for simply by modifying initial conditions of the
simulation. The resulting contribution to flow anisotropy is correlated with
the fireball geometry and causes an increase of the elliptic flow in
non-central collisions. The results are presented for various scenarios with
energy and momentum deposition to clearly demonstrate this effect.
