  We use numerical simulations of molecular cloud formation in the colliding
flow scenario to investigate the reliability of observational estimates of the
angular momenta of early-state, low-mass protostellar cores. We show that, with
suitable corrections for projection factors, molecular line observations of
velocity gradients in NH$_3$ can be used to provide reasonable estimates of
core angular momenta within a factor of two to three, with a few large
underestimates due to unfavorable viewing angles. Our results differ from
previous investigations which suggested that observations might overestimate
true angular momenta by as much as an order of magnitude; the difference is
probably due to the much smoother velocity field on small scales in our
simulations, which result from allowing turbulence to decay and gravitational
infall to dominate. The results emphasize the importance of understanding the
nature of 'turbulent' velocities, with implications for the formation of
protostellar disks during core collapse.

Astrophysics of Galaxies;Solar and Stellar Astrophysics