THE ECOLOGICAL BALANCE OF LOW-MASS STAR-FORMATION REGIONS

It has been quite widely speculated that the momentum injected by bipo lar outflows from young stars into their surroundings might feed the t urbulence of the placental molecular clouds. In this way a balance cou ld be attained, in which the turbulence leads to the formation of low- mass stars, and the outflows from these stars then feed momentum and e nergy into the turbulent motions, counterbalancing the effect of the t urbulent dissipation. For such a balance to be possible, it is clear t hat an efficient coupling between the outflows and the turbulent motio ns is necessary. This paper describes a possible coupling mechanism, i n which a precessing jet is scattered into 'bullets' and 'shells' trav elling in different directions by the interaction with high-density cl umps present in the surrounding environment. The bullet and shell stru ctures have a high interaction cross-section, and are therefore easily trapped within the molecular cloud, in which they deposit the momentu m of the jet in the form of high-vorticity eddies of complex morpholog y.