Protoplanetary Disk Formation in Molecular Cloud Cores

Abstract

Protoplanetary disk formation is investigated by three‐dimensional hydrodynamic simulations. We directly calculate the disk formation from the molecular cloud core, in which about five orders of magnitude of spatial scale is resolved using a nested grid method. We parameterized the rotational energy of the cloud core, and calculated the disk about ∼105 yr after the protostar formation. After the protoplanetary disk becomes unstable against gravity, fragmentation occurs to form gas giant planets when the cloud core has a larger rotational energy at the initial state. On the other hand, a stable disk maintains for ∼105 yr after the protostar formation when the cloud core has a smaller rotational energy. Comparison of observations with our results indicate that gas planets are frequently formed through the gravitational instability in the protoplanetary disk, which possibly accounts for the formation of gas giant planets located far from the central star.