Density perturbations in a collisional fluid induced by a particle on a slightly-eccentric orbit

Abstract

We consider a massive perturber moving along slightly-eccentric orbits through a collisional fluid in flat spacetime. We compute, via a frequency-domain calculation, the density perturbations induced by this massive perturber and reproduce the characteristic spiral wave structure previously computed for circular orbits with time-domain methods. These are needed for extending Barausse's perturbation analysis of relativistic dynamical friction effects on bodies moving through collisional fluids.