14/maio/20 – Formation of satellites in a jovian disc by pebble accretion (M. Sc. Gustavo Madeira , GDOP)

The formation of the Galilean moons of Jupiter (Io, Europa, Ganymede, and Callisto) was investigated by Canup & Ward 2002 and Mosqueira & Estrada (2003), considering a circumplanetary disk composed by gas, embryos, and satellitesimals. The formation of satellitesimals is possible only under special conditions (Shibaike et al., 2017), presenting an open point in their models, along with their difficulty to explain the laplacian resonance 1:2:4 between the satellites Io, Europa, and Ganymede. In this work, we present an alternative model, where the embryos grow by pebble accretion.
The numerical simulations were performed in the N-body integrator Mercury (Chambers, 1999) including the effects of the type I migration (Paardekooper et al., 2010), gas drag (Adachi et al. 1976) and the pebble accretion (Ormel & Liu, 2018). The dynamical system is composed by Jupiter, a gas disk proposed by Canup & Ward (2002) and 30 embryos. Viscosity (αz = 10−3 and 4 × 10−3), disk decay timescale (τ =0.5, 1.0 and 3.0 Myrs) and pebbles-to-gas ratio (700, 1000, 2000 and 3000) are variable parameters.
Preliminary results show that in 1 Myrs embryos in disks with a higher flux of pebbles reach final masses larger than the Galileans masses. In these systems, the satellites present a fast migration and ∼2-3 satellites survive. In disks with 2000 and 300 pebbles-to-gas ratio, ∼7-8 satellites survive; about 4 of them reach the order of the mass of the Galileans. We verified a higher rate of resonance capture in the most viscous disks.