CLUSTER-FORMING MOLECULAR CLOUD CORES

We model a turbulent cloud core ionized by cosmic rays, having Bonnor- Ebert condensations that are both critically stable and cut off from M HD waves in the core. We take these condensations to be the precursors of stars in clusters. The model predicts that such condensations can exist in 'massive'' cores having a FWHM line width greater than 0.9 km s(-1) and a column density greater than 1 x 10(22) cm(-2), as is obse rved in cluster-forming cores in Perseus, Orion, and Cepheus, but cann ot exist in the less turbulent, less opaque ''low-mass'' cores in Taur us, which have no associated clusters. In cluster-forming cores, these condensations are predicted to have mass similar to 1 M-. and radius similar to 0.03 pc, consistent with the mass and spacing of most young stars in clusters. Such critically stable, cutoff condensations may b e identified by their small size and narrow spectral lines, if observe d with sufficient sensitivity, spectral resolution, and angular resolu tion.