The Three-Dimensional Behavior of Spiral Shocks in Protoplanetary Disks

TL;DR

This dissertation investigates the three-dimensional dynamics of spiral shocks in protoplanetary disks, their role in gas giant formation, and related phenomena like chondrule creation, using theoretical models and advanced numerical simulations.

Contribution

It introduces a comprehensive theory for 3D spiral shock structures, explores their implications for planet formation, and develops novel numerical methods for radiation transport and molecular modeling.

Findings

Identification of shock bores in 3D spiral shocks

Assessment of disk stability against fragmentation

Insights into shock-induced chondrule formation

Abstract

In this dissertation, I describe theoretical and numerical studies that address the three-dimensional behavior of spiral shocks in protoplanetary disks and the controversial topic of gas giant formation by disk instability. For this work, I discuss characteristics of gravitational instabilities (GIs) in bursting and asymptotic phase disks; outline a theory for the three-dimensional structure of spiral shocks, called shock bores, for isothermal and adiabatic gases; consider convection as a source of cooling for protoplanetary disks; investigate the effects of opacity on disk cooling; use multiple analyses to test for disk stability against fragmentation; test the sensitivity of GI behavior to radiation boundary conditions; measure shock strengths and frequencies in GI-bursting disks; evaluate temperature fluctuations in unstable disks; and investigate whether spiral shocks can form chondrules when GIs activate. The numerical methods developed for these studies are discussed, including a radiation transport routine that explicitly couples the low and high optical depth regimes and a routine that models ortho and parahydrogen. Finally, I explore the hypothesis that chondrule formation and the FU Ori phenomenon are driven by GI activation in dead zones.