Centrifugal barrier and super-Keplerian rotation in protostellar disc formation

With the advent of ALMA, it is now possible to observationally constrain how disks form around deeply embedded protostars. In particular, recent ALMA C3H2 line observations nearby protostar L1527 have been interpreted as evidence for so-called "centrifugal barrier," where protostellar envelope infall gradually decelerated a stop by centrifugal force in region super-Keplerian rotation. To test concept barrier, which was originally based on angular momentum conserving-collapse rotating particle fixed point mass, we carry out simple axisymmetric hydrodynamic simulations disk formation including minimum set ingredients: self-gravity, rotation, and prescribed viscosity that enables accrete. We find can indeed exist when relatively large but, unlike classic picture infalling material not solely force. The has more specific than its surrounding material, points an origin outward transport (subject constraint expansion envelope), rather spin-up envisioned falls closer center order conserve momentum. For smaller viscosities, rotation weaker or non-existing. conclude that, despite existence some parameter regime, barrier supported our simulations.