3-DIMENSIONAL SIMULATIONS OF PROTOSTELLAR JETS

We present the first results of fully three-dimensional (3D) simulations of supersonic, radiatively cooling jets using the smoothed particle hydrodynamics technique (SPH). Our results qualitatively agree with the two-dimensional (2D) simulations of Blondin, Fryxell, & Konigl (1990), although the removal of the axisymmetry has resulted in relevant structural differences, especially at the jet head where a cold shell is formed from the condensation of shock-heated material. In particular, we found that the shell is not only dynamically unstable but also may undergo oscillations in density, which are attributed to global thermal instabilities. These effects may have important consequences on the dynamics and emission pattern of the observed HH objects associated to young stellar jets. We discuss the implications of our results in the interpretation of the observed properties of the stellar jets and HH objects. We also compare the structure of radiative cooling and adiabatic 3D jets.