LINE FORMATION IN COLLAPSING CLOUD CORES WITH ROTATION AND APPLICATIONS TO B335 AND IRAS-16293-2422

We present radiative transfer models of collapsing clouds with rotation and apply them to B335 and IRAS 16293-2422, the two best candidates of protostellar collapse known to date. By including rotation in the manner of Terebey, Shu, & Cassen (1984), we can reproduce the profiles of several molecular lines not only toward the center position, but also toward a grid of positions near the center. We find that the model of B335 by Zhou et al. (1993) is not affected significantly by the presence of rotation. By including rotation, we can reproduce the observations of IRAS 16293-2422 by Menten et al. (1987); hence, we support the infall interpretation of spectral lines from IRAS 16293-2422 proposed by Walker et al. (1986). We also observed the large-scale rotation of IRAS 16293-2422 in the (CO)-O-18 J = 2 --> 1 line. The observed rotation rate is a factor of 6 smaller than that required to explain the small-scale CS data of Menten et al. (1987). This probably means that the precollapse cloud has differential rotation, possibly due to more efficient magnetic braking on large scales.