A DYNAMICAL STUDY OF THE NON-STAR-FORMING TRANSLUCENT MOLECULAR CLOUD MBM 16: EVIDENCE FOR SHEAR-DRIVEN TURBULENCE IN THE INTERSTELLAR MEDIUM

摘要

We present the results of a velocity correlation study of the high-latitude cloud MBM 16 using a fully sampled 12CO map, supplemented by new 13CO data. We find a correlation length of 0.4 pc. This is similar in size to the formaldehyde clumps described in our previous study. We associate this correlated motion with coherent structures within the turbulent flow. Wuch structures are generated by free shear flows. Their presence in this non-star-forming cloud indicates that kinetic energy is being supplied to the internal turbulence by an external shear flow. Such large-scale driving over long times is a possible solution to the dissipation problem for molecular cloud turbulence.