The Disruption of Binary Star Systems by Massive Black Holes and the Restricted 3-Body Problem
type: CreativeWork
description: Hyper-velocity stars are stars that have been accelerated to speeds in excess of the escape velocity of the galaxy. The first hyper-velocity star observed was found in 2005 by Brown et. al. (2005) and to date we can confirm 25 stars as being hyper-velocity. The small number of these stars discovered is due to the relatively low rate of acceleration events as well as observational methods limiting observations to B type stars. The leading processes by which these stars may be accelerated are binary tidal disruption events in the center of our galaxy. A binary tidal disruption event occurs when a binary star system orbits close to a massive compact object, such as a massive black hole. When this occurs the binary members are separated and one of the binary members gains the orbital energy of its partner, ejecting it at high speeds leaving the partner bound to the black hole. These bound stars, known as S-stars, have been observed and can be used to calculate the mass of the central massive black hole in our galaxy. In this thesis, I present the result of a series of simulations of binary tidal disruption. These simulations provide insight into the required parameters to trigger a binary tidal disruption event as well as the properties of stars ejected via these events. My simulations utilize a restricted three body model to reduce the parameter space that I need to explore to simply the binary orientation, binary phase angle and the penetration depth D, that being the ratio of the closest distance the binary center of mass approaches to the black hole and the tidal radius. This approximation models binaries as having zero energy parabolic orbits but also allows me to model the binary orbit as radial for binaries that have orbits bringing them extremely close to the massive black hole. I will firstly show how the disruption rate behaves as a function of the individual initial conditions of the binary. As the penetration depth shrinks the majority of binaries will be di…
abstract: Hyper-velocity stars are stars that have been accelerated to speeds in excess of the escape velocity of the galaxy. The first hyper-velocity star observed was found in 2005 by Brown et. al. (2005) and to date we can confirm 25 stars as being hyper-velocity. The small number of these stars discovered is due to the relatively low rate of acceleration events as well as observational methods limiting observations to B type stars. The leading processes by which these stars may be accelerated are binary tidal disruption events in the center of our galaxy. A binary tidal disruption event occurs when a binary star system orbits close to a massive compact object, such as a massive black hole. When this occurs the binary members are separated and one of the binary members gains the orbital energy of its partner, ejecting it at high speeds leaving the partner bound to the black hole. These bound stars, known as S-stars, have been observed and can be used to calculate the mass of the central massive black hole in our galaxy. In this thesis, I present the result of a series of simulations of binary tidal disruption. These simulations provide insight into the required parameters to trigger a binary tidal disruption event as well as the properties of stars ejected via these events. My simulations utilize a restricted three body model to reduce the parameter space that I need to explore to simply the binary orientation, binary phase angle and the penetration depth D, that being the ratio of the closest distance the binary center of mass approaches to the black hole and the tidal radius. This approximation models binaries as having zero energy parabolic orbits but also allows me to model the binary orbit as radial for binaries that have orbits bringing them extremely close to the massive black hole. I will firstly show how the disruption rate behaves as a function of the individual initial conditions of the binary. As the penetration depth shrinks the majority of binaries will be di…
author: Brown, H
keywords: QB Astronomy, QC Physics
date published: 2019-06
date modified: 2026-07-24T06:30:28Z
provider: Liverpool Jon Moores University
publisher: Networked Digital Library of Theses and Dissertations
type: WebPage
source organization: Liverpool John Moores University

PropertyValue
property ID: DOI
value: 10.24377/LJMU.t.00010850