Place: 6515 Sterling Hall (coffee at 3:30 pm in 6521 Sterling)
Speaker: Richard Townsend, University of Delaware- Bartol Research Institute
Abstract: Massive, luminous stars are not expected to harbor magnetic fields, owing to their lack of envelope convection zones and associated field-generating dynamos. Puzzlingly, however, it has been known since the 1970s that a small yet growing subset of massive stars possess strong, global-scale fields. These fields channel and confine the stars' supersonic, radioactively driven winds, leading to the formation of glowing, co-rotating magnetospheres that can be observed across the electromagnetic spectrum, from X-rays through to radio.My interest in massive-star magnetospheres stems from the challenge of understanding the rich variety of phenomena they manifest, at a detailed, quantitative level. In my presentation, I aim to illuminate the basic physical processes responsible for the existence of these magnetospheres. Then, with the aid of extensive animations, I willintroduce the new 'Rigidly Rotating Magnetosphere' and 'Rigid Field Hydrodynamics' models that I have developed for understanding magnetospheric signatures at optical, UV and X-ray wavelengths.