Planetesimal Scattering Efficiency of Cold Giant Planet Architectures

Abstract

The discovery of many exoplanets has revealed an incredible diversity of orbital architectures. These orbital configurations are intrinsically linked to the potential for habitable environments within the system, since the gravitational influence of the planets governs the angular momentum distribution within the system. This angular momentum distribution, in turn, alters the planetary orbits and rotational obliquities. In the case of giant planets, their gravitational influence can also produce significant redistribution of volatiles, particularly those that lie beyond the snow line. Here, we present the results of dynamical simulations that investigate the role of cold giant planets in scattering material to inner terrestrial planets. We highlight 10 exoplanetary systems with 2 or more known giant planets beyond the snow line, and adopt a solar system analog template that investigates the scattering of material within the range 3-8~AU. We show that increasing the eccentricity of a Jupiter analog from its present, near-circular, value to a moderate range (0.2-0.3) results in an order of magnitude increase in scattered material to the inner part of the system. The inclusion of a Saturn analog to the dynamical model produces a similar increase, highlighting the importance of multiple giant planets beyond the snow line. However, the addition of analogs to Uranus and Neptune can have a minor negative effect on scattering efficiency through the transfer of angular momentum from the inner giant planets.