Physics Master of Science Thesis Defense by Prabodha Mudalige
When: Monday,
June 5, 2023
10:00 AM
-
12:00 PM
Where: > See description for location
Description: Physics Master of Science Thesis Defense by Prabodha Mudalige
Date: June 5, 2023
Time: 10:00am
Topic: Viscous Evolution of Astrophysical Disks
Location: SENG 108
Zoom Link: https://umassd.zoom.us/j/96470994898?pwd=UHhOcGg2SFE2b3VrbUdnUk53dGNUQT09
Abstract:
Astrophysical disks, such as accretion disks, play a crucial role in various astrophysical phenomena and are of great importance in understanding the formation and evolution of celestial objects. Mass accretion within these disks occurs through angular momentum transport, which arises from an effective viscosity. Understanding the viscous evolution of gaseous disks is crucial for investigating the evolution of astrophysical systems like white dwarf mergers. In this study, we focus on the post-merger accretion disk resulting from the merger of two white dwarfs, a primary progenitor channel for Type Ia supernovae. The differential rotation of the remnant gives rise to a fluid instability known as the magnetorotational instability (MRI), which plays a key role in turbulence and angular momentum transport within the disk.
To investigate the accuracy and limitations of angular momentum transport in the post-merger accretion disk, we employ a model based on a rotating Keplerian system, treating the disk as a ring of viscous fluid. Our simulations utilize FLASH, a parallel adaptive mesh refinement code featuring a higher-order Godunov hydrodynamics solver. The inclusion of hydrodynamical accuracy in a cylindrical geometry is essential for accurately simulating the remnant's behavior over a viscous evolutionary timescale. To ensure the stability of our numerical simulations, we enforce a combination of the viscous and Courant-Friedrichs-Lewy (CFL) time step criteria. We aim to shed light on the mechanisms governing the angular momentum transport and turbulent evolution within the post-merger accretion disk, thus providing valuable insights into the complex nature of astrophysical disks.
ADVISOR(S): Dr. Robert Fisher, Department of Physics
(rfisher1@umassd.edu)
COMMITTEE MEMBERS: Dr. Sarah Caudill, Department of Physics
Dr. Renuka Rajapakse, Department of Physics
NOTE: All PHY Graduate Students are ENCOURAGED to attend.
Date: June 5, 2023
Time: 10:00am
Topic: Viscous Evolution of Astrophysical Disks
Location: SENG 108
Zoom Link: https://umassd.zoom.us/j/96470994898?pwd=UHhOcGg2SFE2b3VrbUdnUk53dGNUQT09
Abstract:
Astrophysical disks, such as accretion disks, play a crucial role in various astrophysical phenomena and are of great importance in understanding the formation and evolution of celestial objects. Mass accretion within these disks occurs through angular momentum transport, which arises from an effective viscosity. Understanding the viscous evolution of gaseous disks is crucial for investigating the evolution of astrophysical systems like white dwarf mergers. In this study, we focus on the post-merger accretion disk resulting from the merger of two white dwarfs, a primary progenitor channel for Type Ia supernovae. The differential rotation of the remnant gives rise to a fluid instability known as the magnetorotational instability (MRI), which plays a key role in turbulence and angular momentum transport within the disk.
To investigate the accuracy and limitations of angular momentum transport in the post-merger accretion disk, we employ a model based on a rotating Keplerian system, treating the disk as a ring of viscous fluid. Our simulations utilize FLASH, a parallel adaptive mesh refinement code featuring a higher-order Godunov hydrodynamics solver. The inclusion of hydrodynamical accuracy in a cylindrical geometry is essential for accurately simulating the remnant's behavior over a viscous evolutionary timescale. To ensure the stability of our numerical simulations, we enforce a combination of the viscous and Courant-Friedrichs-Lewy (CFL) time step criteria. We aim to shed light on the mechanisms governing the angular momentum transport and turbulent evolution within the post-merger accretion disk, thus providing valuable insights into the complex nature of astrophysical disks.
ADVISOR(S): Dr. Robert Fisher, Department of Physics
(rfisher1@umassd.edu)
COMMITTEE MEMBERS: Dr. Sarah Caudill, Department of Physics
Dr. Renuka Rajapakse, Department of Physics
NOTE: All PHY Graduate Students are ENCOURAGED to attend.
Contact: > See Description for contact information
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