  In a granular gas experiment of magnetized particles confined in a thin
layer, the rate of dissipative collisions is tuned by adjusting the amplitude
of an external magnetic field. The velocity statistics are analyzed using the
dynamic and static structure factors of transverse velocity modes. Using the
fluctuating hydrodynamics theory we measure the deviation from kinetic energy
equipartition in this out-of-equilibrium system as a function of the
dissipative collision rate. When the collision rate is decreased, the distance
to equipartition becomes smaller meaning that the dynamical properties of this
granular gas approach by analogy those of a molecular gas in thermal
equilibrium.
