Formation and Structure of Circumplanetary Disks and Envelopes During the Late Stages of Giant Planet Formation

Giant planets are expected to form within circumplanetary disks, which shapetheir formation history and the local environment. Here, we consider theformation and structure of circumplanetary disks that arise during the latestages of giant planet formation. During this phase, when most of the finalmass is accumulated, incoming material enters the Hill sphere and falls towardthe planet. In the absence of torques, the falling parcels of gas conservetheir specific angular momentum and collect into a circumplanetary disk.Generalizing previous work, we consider a range of possible geometries for theflow entering the sphere of influence of the planet. Specifically, we considerfive geometric patterns for the inward flow, ranging from concentration towardthe rotational poles of the system to isotropic flow to concentration along theequatorial plane. For each case, we derive analytic descriptions for thedensity field of the infall region, the disk surface density in the absence ofviscosity, and steady-state solutions for viscous disks. These results, inturn, specify the luminosity contributions of the planet, the circumplanetarydisk, and the envelope. These power sources, in conjunction with thesurrounding material, collectively determine the observational appearance ofthe forming planet. We conclude with an approximate determination of theseradiative signatures.