Azimuthally averaged specific angular momentum, normalized by the Keplerian value, measured in the midplane. Full lines indicate retrograde motion, while dashed lines mark prograde motion. The red curve shows an isothermal simulation (run ISO) with prograde rotation inside the Hill sphere. The black and blue curve correspond to, respectively, the reference simulations RADL27k0.01 and RADL0k0.01. Gray dotted lines indicate two limit cases, gas purely in Keplerian rotation around the core (h_z/h_K = 1) and gas in purely Keplerian rotation around the star, as if no planet were present (Eq. (22)).