  We study the effects of expansion and viscous corrections on the
hydrodynamical medium response to a high energy jet parton. More specifically,
using a semi-analytical Gubser solution to relativistic fluid dynamics,
modifications to the formed Mach cone, diffusive wake, and the momentum flow of
the medium response along and perpendicular to the jet particle, are analyzed
mode-by-mode. This should provide intuition and guidance for analyses of the
experimentally measured jet sub-structure in heavy-ion collisions.
