Capturing the Fire: Flames and Flame Models in Astrophysics

Many explosive astrophysical events are powered by rapid thermonuclear burning, and the outcome of an event, the distribution and energy of nuclides in the remnant, depends sensitively on the details of this burning. Modeling astrophysical explosions presents a challenge because the disparity between the length scale of the star and that of thermonuclear flames can be 10-12 orders of magnitude. I will present an overview of thermonuclear flames and combustion and the effects of fluid instabilities and background turbulence. I will also describe efforts to capture the essence of sub-grid-scale burning in parameterized models and the development of post-processing routines used to obtain detailed composition by integrating density and temperature histories of Lagrangian tracer particles. Finally, I will present simulations of thermonuclear supernovae that combine these elements to explain observed trends in the brightness of events.

Bio

Alan Calder is an associate professor in the Astronomy Group within the Dept of Physics and Astronomy at Stony Brook University. His research is in the field of nuclear astrophysics, and his work involves simulating explosive astrophysical phenomena. Dr. Calder also has extensive experience with large-scale computing. Prior to coming to Stony Brook, Dr. Calder had research appointments at the National Center for Supercomputing Applications at the University of Chicago, where he was at the Center for Astrophysical Thermonuclear Flashes. He was also an instructor at the School of the Art Institute in Chicago. Alan Calder’s research is principally in bright stellar explosions known as Type Ia supernovae. These events produce and disseminate heavy elements and are therefore important for galactic chemical evolution. The light curves of these events can be standardized and thereby used as distance indicators for cosmology studies investigating the expansion history of the Universe.

Speaker

Alan Calder

Date

Thursday, February 1, 2018

Time

1 pm - 2 pm

Location

IACS Seminar Room