Time: | Tuesday, November 03, 2020, 10:30am |
Title: | Introduction to Warped Accretion Discs |
Speaker: | Hongping Deng (Cambridge) |
Location: | Online via Zoom (Meeting ID: 920 6438 7397 PW: 201103) |
ABSTRACT
Warped accretion discs are common around black holes and stars. There is growing indirect observational evidence for warped circumstellar discs around young stars, indicated by shadows cast by the warps. I will briefly review the rich warped disc dynamics, including warp diffusion, bending wave propagation and disc breaking. I will focus on a hydrodynamic instability due to resonance between pairs of inertial waves and warp induced shear flow. The ensuing turbulence, captured for the first time in a global simulation, damps relative orbital inclinations and leads to a decrease in the angular momentum deficit. As a result, the warp undergoes significant damping within one bending-wave crossing time. Observed protoplanetary disc warps are likely maintained by companions or aftermath of disc breaking.
Host: Xuening Bai
Slides: