Sean Raymond (Obs. de Bordeaux)
Jeudi 19 Janvier - 11 h 00
Salle Manuel Forestini - IPAG
The eccentric orbits of the known extrasolar giant planets provide evidence that most planet-forming environments undergo violent dynamical instabilities. Here, we numerically simulate the impact of giant planet instabilities on planetary systems as a whole. We find that populations of inner rocky and outer icy bodies are both shaped by the giant planet dynamics and are naturally correlated. The orbital distributions of outer planetesimal disks can be drastically altered by the giant planets ; in the most extreme cases they can be converted into 100 AU-scale nearly-isotropic clouds. Strong instabilities - those with very eccentric surviving giant planets - completely clear out their inner and outer regions. In contrast, systems with stable or low-mass giant planets form terrestrial planets in their inner regions and outer icy bodies produce dust that is observable as debris disks at mid-infrared wavelengths. Fifteen to twenty percent of old stars are observed to have bright debris disks (at λ 70μm) and we predict that these signpost dynamically calm environments that should contain terrestrial planets.
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