  Janus colloids propelled by light, e.g., thermophoretic particles, offer
promising prospects as artificial microswimmers. However, their swimming
behavior and its dependence on fluid properties and fluid-colloid interactions
remain poorly understood. Here, we investigate the behavior of a thermophoretic
Janus colloid in its own temperature gradient using numerical simulations. The
dissipative particle dynamics method with energy conservation is used to
investigate the behavior in non-ideal and ideal-gas like fluids for different
fluid-colloid interactions, boundary conditions, and temperature-controlling
strategies. The fluid-colloid interactions appear to have a strong effect on
the colloid behavior, since they directly affect heat exchange between the
colloid surface and the fluid. The simulation results show that a reduction of
the heat exchange at the fluid-colloid interface leads to an enhancement of
colloid's thermophoretic mobility. The colloid behavior is found to be
different in non-ideal and ideal fluids, suggesting that fluid compressibility
plays a significant role. The flow field around the colloid surface is found to
be dominated by a source-dipole, in agreement with the recent theoretical and
simulation predictions. Finally, different temperature-control strategies do
not appear to have a strong effect on the colloid's swimming velocity.
