THE DYNAMICS OF A JET IN A SUPERSONIC SIDE WIND

We study the problem of a jet ejected from a source, which has a supersonic relative velocity with respect to the surrounding environment. We find that while the adiabatic problem (appropriate for extragalactic jets) has to be solved numerically, the isothermal problem (appropriate for Herbig-Haro jets) does have a complete analytic solution. Furthermore, we show that the adiabatic solutions (for any value of the specific heat ratio gamma) converge to the isothermal solution in the region close to the stagnation point of the flow. Because of this, the analytic isothermal solution can be used for comparisons with observations of curved jets in both the isothermal and adiabatic regimes. Finally, we present a comparison of our model with observations of the curved Herbig-Haro now HH 30.