Argonne National Laboratory

Flash Code: Studying Astrophysical Thermonuclear Flashes

TitleFlash Code: Studying Astrophysical Thermonuclear Flashes
Publication TypeJournal Article
Year of Publication2000
AuthorsRosner, R, Calder, AC, Dursi, J, Fryxell, B, Lamb, DQ, Niemeyer, JC, Olson, K, Ricker, P, Timmes, FX, Truran, JW, Tufo, HM, Young, Y-N, Zingale, M, Lusk, EL, Stevens, RL
JournalComputing in Science and Engineering
Date Published03/2000

The Center for Astrophysical Thermonuclear Flashes at the University of Chicago---a collaboration between scientists primarily at Chicago and Argonne National Laboratory---studies the longstanding problem of thermonuclear flashes on the surfaces of compact stars (such as neutron stars and white dwarfs) and in the interior of white dwarfs (such as Type Ia supernovae). Our central computational challenge is the breadth of physical phenomena involved. These range from accretion flow onto the surfaces of these compact stars to shear-flow and Rayleigh-Taylor instabilities on the stellar surfaces, nuclear burning ignition under conditions leading to convection, stellar envelope expansion, and the possible creation of a common-envelope binary star system. Many of the physical phenomena we encounter have counterparts in the terrestrial realm (in more extreme versions): convection and turbulence at huge Reynolds and Rayleigh numbers, convective penetration of stable matter, state equations for high density matter, nuclear processing, radiation hydrodynamics, and interface dynamics (including mixing instabilities and burning front propagation). Perhaps the most spectacular phenomenon with no obvious terrestrial counterpart is the interaction of two binary stars when one of them expands during a nova outburst and swallows its companion.