  I use the space-time distribution of energy and momentum deposited by a fast
parton traversing a perturbative quark-gluon plasma as a source term for the
linearized hydrodynamical equations of the medium. A method of solution for the
medium response is presented in detail. Numerical results are given for
different values of the shear viscosity to entropy density ratio, $\eta/s$, and
speed of sound, $c_s$. Furthermore, I investigate the relevance of finite
source structure by expanding the source term up to first order in gradients of
a $\delta$ function centered at the fast parton and comparing the resulting
dynamics to that obtained with the full source. It is found that, for the
source term used here, the medium response is sensitive to the finite source
structure up to distances of several fm from the source parton.
