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dc.contributor.advisorYoudin, Andrew
dc.contributor.authorLi, Rixin
dc.creatorLi, Rixin
dc.date.accessioned2020-09-25T01:56:40Z
dc.date.available2020-09-25T01:56:40Z
dc.date.issued2020
dc.identifier.urihttp://hdl.handle.net/10150/645800
dc.description.abstractA critical step in planet formation is to build super-kilometer-sized planetesimals out of dust particles in gaseous protoplanetary disks. The origin of planetesimals is crucial to understanding the Solar System, exoplanetary systems, and circumstellar disks. In this thesis, I present my work on exploring and better understanding promising planetesimal formation pathways with extensive numerical modeling and robust statistical analyses, with a main focus on the streaming instability (SI), a mechanism to aerodynamically concentrate solids in disks and trigger gravitational collapse to form planetesimals. The first study focuses on the numerical robustness of the SI, where I demonstrate that the nonlinear particle clumping by the SI is robust to various numerical setups. In the next study, I carry out the SI simulations including particle self-gravity with the highest resolution to date, which produces a broad and top-heavy initial mass distribution of planetesimals. Necessitated by analyzing my simulations, I have built and published an efficient clump-finding code, PLAN, capable of robustly identifying and characterizing self-bound clumps. I then present the highlights from analyses of the demographics of planetesimals. I first apply a maximum likelihood estimator to fit a suite of parameterized models with different levels of complexity to the simulated mass distribution. I show that our simulations produce different mass distributions with different aerodynamic properties of the disk and participating solids. I will report the first evidence for a turnover in the low mass end of the planetesimal mass distribution. With PLAN, I also find that the clumps in our simulations possess excess angular momenta that might explain why all planetesimals formed as binaries/multiples and the high binary fraction among Cold Classical Kuiper Belt Objects. Furthermore, the predicted binary orbits show a broad inclination distribution with 80% of prograde orbits, excellently matching the observations of trans-Neptunian binaries. Finally, I conclude with the key results in this thesis and discuss the future directions for planetesimal formation studies, with some pioneering results from my on-going work.
dc.language.isoen
dc.publisherThe University of Arizona.
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction, presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
dc.subjectformation
dc.subjecthydrodynamics
dc.subjectinstabilities
dc.subjectplanetesimals
dc.subjectplanets
dc.subjectprotoplanetary disks
dc.titleSimulating Planetesimal Formation in the Kuiper Belt and Beyond
dc.typetext
dc.typeElectronic Dissertation
thesis.degree.grantorUniversity of Arizona
thesis.degree.leveldoctoral
dc.contributor.committeememberRieke, George
dc.contributor.committeememberKratter, Kaitlin
dc.contributor.committeememberApai, Daniel
dc.contributor.committeememberEisner, Joshua
thesis.degree.disciplineGraduate College
thesis.degree.disciplineAstronomy
thesis.degree.namePh.D.
refterms.dateFOA2020-09-25T01:56:40Z


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