Supervisor: Dr. Shazrene Mohamed (UCT and SAAO)

Stellar winds are ubiquitous and one of the primary channels through which stars lose mass and return nuclear enriched material to galaxies. For runaway stars moving supersonically through the interstellar medium (ISM), the collision of the stellar wind with the surrounding gas produces an arc-like structure called a bow shock. Using relatively simple physics, bow shocks can be powerful probes of properties of the ISM, stellar winds and dynamics.

In this project, the latest and most detailed hydrodynamic and radiative transfer codes will be used to investigate the formation of bow shocks, comparing the models with high-resolution observations.

Honours: Students will complete a literature review on bow shocks and hydrodynamics methods. They will then run supercomputer simulations of bow shocks for different parameters. Analysis and visualization tools will be used to synthesize the results and to make animations of the models.

Masters: In addition to the above, students will combine hydro-code simulations with post-processing radiative transfer tools to compare the models to observations.

For this project students must be comfortable with basic unix/linux commands, and python and/or C/Fortran programming experience will also be very useful. Please email me for further details and to make arrangements to discuss the project.

Email: shazrene@saao.ac.zaOffice: SAAO, Main Building, west wing, ground floorUCT, RW James 5.33

Runaway stars and the formation of bow shocks

Bow shock around planetary nebula, Sh 2-188; stellar velocity ~125 km/s

Bow shock around red supergiant star, Betelgeuse; stellar velocity ~30 km/s

3D simulations: stellar velocity 70 km/s (left) and 30 km/s (right).