Accretion shocks of forming gas giants (2022)

The final stage of gas giant formation involves accreting gas from the parent protoplanetary disk. If the infalling gas likely approaches a free-fall velocity, creating an accretion shock, it can lead to strong shock heating and radiation. We investigate the kinematics and energetics of such accretion shocks using 1D radiation hydrodynamic simulations. We find that the hydrogen may be dissociated by the luminous accretion shock when the accretion rate is high, leading to hot-start planet formation.
  The paper can be found here.

accprof accprof Jupiter's accretion profile. Left: at high accretion rate, the hydrogen in the incoming gas will be dissociated by the radiation emitted by the accretion shock, increasing the initial entropy of forming gas giants. Right: at lower accretion rate, the hydrogen is not dissociated.