Physics
Scientific paper
Dec 2002
adsabs.harvard.edu/cgi-bin/nph-data_query?bibcode=2002agufm.p12c..03c&link_type=abstract
American Geophysical Union, Fall Meeting 2002, abstract #P12C-03
Physics
6218 Jovian Satellites
Scientific paper
We consider a scenario in which the regular satellites of gas giants form within circumplanetary accretion disks produced during the end stages of gas accretion (e.g., Lubow et al. 1999; DÁngelo et al. 2002). Assuming some inflow rate of gas and solids, a steady-state circumplanetary gas disk is produced through a balance of the inflow supply and the diskś internal viscous evolution (Lynden-Bell and Pringle 1974). The diskś radial thermal profile is determined by a balance of radiative cooling from the disk with heating from the planetś luminosity, viscous dissipation, and ambient nebular insolation. Once in circumplanetary orbit, inflowing solids accumulate into objects large enough to decouple from the gas on time scales much shorter than their lifetime against inward decay due to gas drag. The total mass of solids thus builds-up over time, with satellites accreting at a rate regulated by the inflow flux. In the Jovian system, the ice-rich composition of Ganymede and Callisto, as well as the apparently only partially differentiated state of Callisto (e.g., Anderson et al. 1998, 2001), both provide constraints on the disk environment in which the regular satellites formed. In addition, the presence of the four large Galileans implies that at least the last generation of satellites were able to survival against radial inward decay due to Type I interaction with their precursor disk. We have found that these constraints can be best satisfied for a circumjovian disk supplied by a slow gas inflow rate, F, of F < MJ/(few x 106 yrs), where MJ is a Jovian mass (Canup and Ward 2002, in press). Such a slow inflow rate yields a much lower steady-state gas surface density than is implied by augmenting the mass of the current satellites to solar elemental composition, as has been done previously (e.g., Lunine and Stevenson 1982; Coradini et al. 1989). This implies that the overall formation times of the Galilean satellites were long (> 105 years) and that the end stages of growth occurred in a relatively gas free environment. In addition, some inward migration of Galilean-sized satellites due to Type I torques is predicted for many disk conditions.
Canup Robin M.
Ward William R.
No associations
LandOfFree
Satellite Formation around Gas Giant Planets does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.
If you have personal experience with Satellite Formation around Gas Giant Planets, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Satellite Formation around Gas Giant Planets will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-1891894