Events on Tuesday, December 17th, 2024
- Odd Radio Circles and the Dynamics of Nonthermal Plasma
- Time: 12:00 pm - 2:00 pm
- Place: B343 Sterling
- Speaker: Yiting Wang, Physics PhD Graduate Student
- Abstract: Odd Radio Circles (ORCs) are a newly discovered class of ring-like radio sources, with diameters of ∼ 1 arcminute, steep spectral indices between 0.5 and 1.7, and estimated physical radii on the order of several hundred kiloparsecs. The physical nature and origins of ORCs remain unclear. In the first project, I present results from three-dimensional magnetohydrodynamic (MHD) simulations that model ORCs as synchrotron-emitting vortex rings produced by Richtmyer-Meshkov instability during shock-bubble interactions. A planar shock wave encounters a low-density bubble, leading to the formation of torus-like structures whose predicted properties align with observations of ORCs. The second project explores an alternative hypothesis that ORCs are end-on projections of late-stage evolution of radio bubbles driven by active galactic nuclei (AGN) jets. We model AGN jets viewed along the line of sight to assess whether their emission profiles and morphologies can account for the characteristics of ORCs. In the final part of the presentation, I outline my ongoing work on radiation drag in relativistic jets. This project aims to understand how interactions with radiation fields affect the energy transfer and instability in jets dynamics.
- Host: Sebastian Heinz