Effects on Supernovae and their Remnants of Asymmetric Envelopes Caused by Outflow from Binary-star Progenitors

North Carolina State University, Raleigh NC

Investigators

Abstract

The violent star explosions, known as supernovae, are responsible for many features of our Universe. They produce and distribute many of the heavy elements that make up stars, new planets, and also people. The energy supernovae release into the interstellar gas heats and stirs it, and some of that energy goes to accelerating a few subatomic particles to extreme energies -- the enigmatic cosmic rays that fill our Galaxy and constantly rain down on the Earth. In the last few thousand years, several Galactic supernovae were visible at Earth and carefully recorded by naked-eye observers. The remnants of those supernovae, expanding gas clouds emitting radio waves, X-rays, and visible light, can now be studied in detail, along with hundreds of older remnants from supernovae too distant to be seen on Earth with the naked eye. This proposal will model the effects of supernovae that occur in systems with two stars gravitationally bound to each other. Recent evidence suggests that many supernovae originate in binary systems, pairs of stars orbiting one another. The more massive stars shed material as they age, particularly in the stages just prior to explosion, so the explosions take place in a complicated environment of gas. These investigators will compute state-of-the-art simulations of pre-supernova environments, and then model the explosion, to see what effects it has on the appearance of the supernovae at the time of the event, and on the remnants of the events, which are still thousands of years later. The investigators hope to identify particular features that such supernovae and remnants might show that would be clues to the environments that gave rise to them. In addition, a few particular objects, such as historical remnants from supernovae seen at Earth in the last few hundred years, will be studied, to try to identify the types of stars that created the explosions. The investigators will use high-performance computing systems at national facilities, and will train students in the most up-to-date applications of computing to complex problems. Improving our understanding of supernovae adds an essential piece to the grand narrative of the nature of our Universe and the place of humanity in it.