Research, Alice Quillen

Celestial Mechanics, Circumstellar Disk Morphology and Exoplanets

I extended theory for resonance capture to cover the non-adiabatic limit (2006). I developed a theoretical framework attempting to account for stability timescales in closely packed multiple planet systems (2011,2014). This work leverages three-body resonances. We explored numerically the dynamics of multiple planet systems in the presence of debris. We find that collisions between planets and embryos are needed to explain the architecture of compact planetary systems such as Kepler 36. A body of work uses parallel simulations on GPUs to do particle integration.

In an attempt to understand the instability of multiple planet systems, I disected one of Rob French's simulations of the Uranian satellite system. The result is improved estimates of three-body resonance strengths, and resonance overlap parameters for bodies in chains of mean motions resonances. Resonant Chains and Three-body Resonan ces in the Closely-Packed Inner Uranian Satellite System , ADS. This paper adds to a previous paper proposing that three body resonances are the source of instability for multiple planet systems. Three Body Resonance Overlap in Closely Spaced Multiple Planet Systems. arxiv
A scenario for the origin of the Kepler 36 system. Explaining both the proximity and high density contrast of the two planets and involving encounters between planets and planetary embryos. Origin Scenarios for the Kepler 36 planetary system (ADS), arxiv Talk Nov 2013 at Cornell pptx Talk Oct 2014 in Kansas pptx
Alex Moore's thesis papers: Scenarios for the HR8799 and KOI730 planetary systems, focusing on the dynamics of multiple planet systems with external debris and explored using a GPU accelerated integrator: Effects of a planetesimal debris disc on stability scenarios for the extrasolar planeta ry system HR 8799, Limits on orbit crossing planetesimals in the resonant multiple planet system, KOI-730, arxiv. These works use our integrator QYMSYM: A GPU-accelerated hybrid symplectic integrator that permits close encounters (New Astronomy), on astroph,
General theory for predicting the likelihood of resonant capture covering the non-adiabatic limit, Reducing the Probability of Capture into Resonance , PDF , Errata
Related to the proposed outer eccentric planet in the Fomalhaut system: Chaotic zone boundary for low free eccentricity particles near an eccentric planet, PDF
On irregular satellite capture via tidal disruption of binary plenatesimals in migrating planetary systems (Imran's!) Capture of Irregular Satellites via Binary Planetesimal Exchange Reactions in Migrating Plan etary Systems (astroph)
We argue that Pluto mass planetary embryos are embedded in the disks of AU Microscopii, Beta Pictoris and Fomalhaut, Planetary embryos and planetesimals residing in thin debris disks , astro-ph , PDF
On the morphology of protostellar disks (with Peggy!), Driving spiral arms in the debris disks of HD 100546 and HD 141569A , PDF and The Evolution of Protoplanetary Disk Edges , PDF and Planets Rapidly Create Holes in Young Circumstellar Disks and Observational Properties of Protoplanetary Disk Gaps
More on the morphology of protostellar disks (Pasha's paper!), The formation of an eccentric gap in a gas disk by a planet in an eccentric orbit
How to send alot of stuff into a star and produce stargrazing comets by sweeping resonances through a planetesimal belt, Production of Star-grazing and Star-impacting Planetesimals via Orbital Migration of Extrasolar Planets , PDF And yet stars are not polluted, Using a Hipparcos-derived Hertzsprung-Russell Diagram to Limit the Metallicity Scatter of Stars in the Hyades: Are Stars Polluted? , PDF This initial study showed with photometry that stars in an open cluster have nearly identical metallicity; scatter delta[Fe/H]<0.03. This limit has been confirmed and for more clusters with spectroscopic studies.