Working surfaces in radiative, non-top hat jets

Most models of radiative jets have been computed for the special case of a top hat initial cross section. This paper discusses the dynamics of both leading and internal working surfaces in jets with more general initial cross sections, based on both an analytic, “thin shell” model, and on a full numerical simulation. We find that a non-top hat cross section for the jet ram pressure first leads to a strong curvature of the working surface shocks, and at longer timescales to the formation of awarm, dense “nose cone”. These results have interesting implications for comparisons between radiative jet models and observations of Herbig-Haro objects.