Institute of Astronomy

Accretion of Jupiter-mass Planets

SpeakerTalk DateTalk Series
Judit Szulagyi28 July 2014Across HR 2014 Posters

Abstract

The core accretion model predicts runaway gas accretion phase for giant planets, which does not stop until the planet opened a deep gap after acquiring 5-10 Jupiter-masses. However, observational evidences show that this massive giant planets are rare in the universe. In order to solve this contradiction, we performed 3D hydrodynamical simulations of a Jupiter-mass planet in both isothermal and adiabatic settings. We were interested in understanding how the circumplanetary disk (CPD) acts as a regulator of the accretion process. In the isothermal simulation, we found that the ~90% of the mass accreted by the planet comes from the vertical inflow in the planetary gap; this inflow is part of a meridional circulation in the circumstellar disk. We distinguished among the different accretion mechanisms and uncovered that in the zero viscosity limit, the main mechanism allowing the CPD to lose angular momentum is the torque exerted by the star via the spiral density wave. In this limit, we found that Jupiter's mass doubling time is comparable to the photoevaporation timescale (i.e. half Myr), which could explain the observed variety of planetary masses, including the lack of very massive planets. This estimate, though, is uncertain, because isothermal simulations cannot approximate the CPD's mass. Thus, we further developed a hydrodynamic code to handle the energy equation, stellar irradiation and a simplified radiative transfer, in order to address the maximal mass of the CPD in the zero viscosity limit. The results and comparisons of both simulations will be presented at the conference.

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