Establishing the Diversity of Super-Earth Systems with a Continuum of Formation Conditions
Abstract
Multi-planet systems observed by Kepler that contain super-Earths exhibit a diversity of orbital and compositional properties. Here we investigate what planetary system outcomes arise from a range of protoplanetary disk solid surface densities and dissipative conditions shortly before disk dispersal, through simulating the giant impact phase of planet formation and subsequent dynamical evolution. We also compare the orbit distributions of these outcomes to the multi- transiting systems observed by the Kepler mission. For the same degree of dissipation from a gaseous disk and with no orbital migration, we find that larger solid surface densities lead to more tightly packed, flatter systems than smaller solid surface densities. We find that the spread in mass-radius relation observed in the Kepler population can also be explained with a wide range of solid surface densities, where small solid surface densities lead to rocky, dense planets and large solid surface densities lead to larger, gaseous planets. The distributions of the period ratios, spacings in mutual Hill radii, and transit duration ratios of adjacent planets — as well as the distribution of planet multiplicity — arising from these solid surface densities in conjunction with moderate gas damping (corresponding to a protoplanetary disk depleted by a factor of 100 in mass before disk dispersal) agree with the distributions of observed systems. These disk conditions can also produce super Earth systems with resonant chains, successive pairs near and in mean motion resonances.
- Publication:
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AAS/Division for Extreme Solar Systems Abstracts
- Pub Date:
- August 2019
- Bibcode:
- 2019ESS.....431701M