  We study the response of an infinite, asymptotically static N=4 plasma to a
generic localized source in the probe approximation. At large distances, the
energy momentum tensor of the plasma includes a term which satisfies the
constitutive relations of linearized hydrodynamics, but it can also include a
non-hydrodynamical term which contributes at the same order as viscous
corrections, or even at leading order in some cases. The conditions for the
appearance of a laminar wake far behind the source and its relevance for
phenomenological models used to explain di-hadron correlations are discussed.
We also consider the energy momentum tensor near the source, where the
hydrodynamical approximation can be expected to break down. Our analysis
encompasses a wide range of sources which are localized in the bulk of AdS,
including trailing strings, mesonic and baryonic configurations of strings, and
point particles.
