Speaker
Description
Giant planets play a crucial role in shaping planetary systems. When formed early, they can dynamically organize surrounding planetesimals, inducing apsidal alignment that suppresses random velocities—even if eccentricities are excited—thereby promoting the growth of inner rocky planets. Under such conditions, giant planets may support, rather than hinder, terrestrial planet formation.
However, when giant planets undergo dynamical instabilities, their impact turns destructive. Radial velocity surveys show that giant planets often have modest eccentricities and are clustered near the snow line, hinting at histories of mutual scattering. In such cases, inward-scattered giants can disrupt or destroy inner systems, potentially explaining the broken resonance chains observed in Kepler super-Earth systems.
These same instabilities are also expected to eject planets into interstellar space, forming free-floating planets (FFPs). While giant planets are traditionally thought to dominate this population, our population synthesis models—calibrated to microlensing surveys and realistic stellar IMFs—suggest otherwise. The FFP population is dominated by Neptune-like planets, due to their abundance around low-mass stars and greater likelihood of being ejected via mutual scattering.
In this talk, I will explore these interconnected processes, focusing on how planetary dynamics shape both bound and unbound planetary orbital architectures.
| Session Selection | Astronomy and Astrophysics |
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