Simultaneous formation of solar system giant planets

O. M. GUILERA; A. FORTIER; A. BRUNINI; O. G. BENVENUTO

Nantes

Congreso; EPSC-DPS Joint Meeting 2011; 2011

We study the formation of the solar system giant planets in connection with several parameters that describe the protoplanetary disk. We aim to establish which conditions enable their simultaneous formation in line with the initial configuration proposed by the Nice model. We focus on the conditions that lead to the simultaneousformation of two massive cores, corresponding to Jupiter and Saturn, which are able to reach the cross-over mass (where the mass of the envelope of the giant planet equals the mass of the core, and gaseous runway starts), while two other cores should be able to grow up to te mass of the icy giants. We compute the in-situ, but simultaneous planetary formation, employing the numerical code introduced in ourprevious work (Guilera et al., 2010) for different density profiles of the protoplanetary disk. Planetesimal migration is taken into account and planetesimals are considered to follow a size distribution between r_p^{min} (free parameter) and r_p^{max}= 100 km. The core?s growth is computed according to the oligarchic growth regime. Wefind that the simultaneous formation of the giant planets ?in the context of the Nice model? is favored by flat surface density profiles. The formation time-scale agrees with the estimates of disk lifetimes if a significant mass of the solids accreted by the planets is contained in planetesimals with radii < 1 km. Furthermore, we find that under certain conditions of the disk, the formation timescale of the four planets is the same.