Tidal Disruption Events Around Tight Black Hole Binaries

Snyder, Cade

Tidal Disruption Events Around Tight Black Hole Binaries

Persistent URL

https://dspace.allegheny.edu/handle/10456/56886

Author(s)

Snyder, Cade

Date Issued

April 2023

Abstract

Simulations of stellar clusters tell us that binary black hole systems can form through both dynamical and stellar evolutionary channels. From observations of black hole mergers at The Laser Interferometer Gravitational-Wave Observatory (LIGO), we have evidence that the formation of black hole binaries is common in nature. When a star approaches close to a black hole, the tidal forces can rip the star apart, in a process called a tidal disruption event (TDE). TDEs can be simulated using smoothed particle hydrodynamic (SPH) codes, such as Starsmasher. When running simulations of TDEs, tiny changes in initial starting parameters can have a profound impact on how much matter is bound to the black hole and how much is ejected from the system. While TDEs around black holes (especially supermassive black holes) have been thoroughly researched in the past, there has been little inquiry into the effect of TDEs around black hole binaries (BBHs). This study analyzes the changes in mass, angular momentum, eccentricity, and semi-major axis of BBH systems as a result of a gravitational encounter and/or tidal disruption event with an incoming star. The initial periapsis and inclination of the incoming star are varied, as well as the initial eccentricity and semi-major axis of the binary. Potential correlations were discovered between changes in initial eccentricity and changes in mass ejected, common envelope mass, and apparent changes in angular momentum. BBHs with higher eccentricities were observed to have their eccentricities and semi-major axes changed less as a result of a TDE. Analysis of runs revealed binary hardening was present in simulations where no TDE occurred, but TDEs caused binary softening. Changes in inclination showed a potential correlation between simulations resulting in complete TDEs as opposed to TDEs in which the star was ejected from the system.

Major

Physics

First Reader(s)

Lombardi, James C., Jr. (Jamie)