Topic 67: Solar System: GeneralPoster PresentationThe migration of the Galilean satellites during formation due to interactions with the circumjovian disk
is studied. In the gas-starved disk model proposed by Canup & Ward (2002, 2006), the Galilean
satellites are the last generation of satellites formed in the circumjovian disk, and their migration
and accretion depend on disk viscosity, opacity and material inflow rate. Relaxing the migration to
non-isothermal type I regime (e.g. Paardekooper et al. 2010) allows the satellites to migrate outwards
in optically-thick disk regions, and there is a position where the disk torque is zero. This contrasts with
278the results in the isothermal type I regime in which the satellites always migrate inwards. Including
the effect of temperature dependence of disk opacity can produce multiple zero-torque positions in
the circumjovian disk. As the disk depletes, these zero-torque positions shift towards Jupiter. Under
this setting, a satellite at a range of initial locations will eventually converge to near one of these
zero-torque positions, but stays at a fixed distance away (with the distance depending on satellite
mass), so that it is moving inwards with the zero-torque position. However, if the satellite starts at
a large-enough distance from Jupiter, it may move in a trajectory that does not converge to any of
these zero-torque positions and survives to the end. The effect of satellite growth and variation of disk
parameters on satellite migration will be discussed. The migration in multiple satellite system, and how
these settings can possibly result in the Laplace resonance among the Galilean satellites, will be also
investigated.
This work is supported in part by Hong Kong RGC grant HKU 7030/11Ppublished_or_final_versio
