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On the dynamics in planetary systems, globular clusters and galactic nuclei

Bradnick, Benjamin Thomas George (2017)
Ph.D. thesis, University of Birmingham.

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N-body simulations are used to investigate the dynamics of planetary systems based on the observed period-radius distribution by Kepler. The stability of the distri- bution is tested using integrations of 2,000 systems and with the addition of a Jupiter-like perturber in an aligned and inclined configuration sufficient for Lidov- Kozai (LK) oscillations. ∼ 67% of planetary systems are found stable, falling to ∼ 62% and ∼ 48% with an aligned or inclined giant perturber. Planet ejections are rare. Instability timescales of systems are predicted by spacing and multiplicity of planets, but exceptions are common. Evolution of select individual systems are investigated and classified.

The dynamics of stellar binaries on eccentric orbits around a massive black hole (MBH) in the empty loss cone (LC) are also explored. The LK mechanism is sup- pressed by two-body relaxation from stars in galactic nuclei whilst tidal perturba- tions from the MBH excite the eccentricity of the binary to produce mergers in ∼ 75% of simulations. Stellar tides circularise the binaries and produce low velocity mergers. Enhanced magnetic fields in merger products could explain relativistic jet formation in tidal disruption events (TDEs).

A method is presented for rapidly calculating the stellar evolution of stars with masses \[m=8.0-300.0M_\odot\] and metallicities \[-4.0\leq [Z/H]\leq 0.5\] that can be incorporated into future n-body simulations.

Type of Work:Ph.D. thesis.
Supervisor(s):Farr, Will and Mandel, Ilya
School/Faculty:Colleges (2008 onwards) > College of Engineering & Physical Sciences
Department:School of Physics and Astronomy
Keywords:galactic nuclei, n-body, simulations, dynamics, exoplanets, dynamical stability
Subjects:QB Astronomy
QC Physics
Institution:University of Birmingham
ID Code:7826
This unpublished thesis/dissertation is copyright of the author and/or third parties. The intellectual property rights of the author or third parties in respect of this work are as defined by The Copyright Designs and Patents Act 1988 or as modified by any successor legislation. Any use made of information contained in this thesis/dissertation must be in accordance with that legislation and must be properly acknowledged. Further distribution or reproduction in any format is prohibited without the permission of the copyright holder.
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