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Magnetic Braking in Neutron Star Low Mass X-Ray Binaries

  • Author / Creator
    Van, Kenny
  • In this thesis, we investigate the effectiveness of theoretical descriptions of angular momentum loss in stars due to the presence of magnetic fields, a process commonly known as magnetic braking. The most widely used description of magnetic braking is the so-called Skumanich prescription, which can effectively describe the angular momentum evolution of stars similar to our Sun, but results in significant discrepancies in both more evolved stars and binary systems. First I will review some of the current fundamentals of binary systems and binary evolution along with a derivation of the Skumanich magnetic braking. Following this review, I introduce a boosted Skumanich prescription which includes the effects of stellar wind loss and convective turnover time. While this magnetic braking prescription more effectively reproduces observed persistent low-mass X-ray binaries than the commonly used Skumanich prescription, the most effective form of the boosted Skumanich prescription uses ad-hoc wind and convection boosting. The second magnetic braking prescription introduced is the Convection and Rotation Boosted (CARB) magnetic braking that explicitly accounts for both the wind and convection leading to a more physical description of magnetic braking. After demonstrating the effectiveness of CARB magnetic braking, I use a comprehensive grid of simulated systems to determine the formation rates of progenitor binaries necessary to reproduce observed LMXBs. The progenitor search of observed LMXBs also revealed gaps in the observed parameter space where I propose some observed LMXBs with incomplete observed quantities may lie. Finally, I summarize the key results of this work and propose future work on this topic of research.

  • Subjects / Keywords
  • Graduation date
    Fall 2021
  • Type of Item
    Thesis
  • Degree
    Doctor of Philosophy
  • DOI
    https://doi.org/10.7939/r3-q3k5-4693
  • License
    This thesis is made available by the University of Alberta Libraries with permission of the copyright owner solely for non-commercial purposes. This thesis, or any portion thereof, may not otherwise be copied or reproduced without the written consent of the copyright owner, except to the extent permitted by Canadian copyright law.