Astrophysics simulation using OLCF resources lands cover of Science

In this image, tubes represent paths of gas falling into a supernova, deflected by an accretion shockwave (horizontal width of 600 km); colors represent different velocities. Visualization: Hongfeng Yu and Kwan-Liu Ma, University of California-Davis and the SciDAC Institute for Ultra-Scale Visualization; Simulation: John Blondin, North Carolina State University.

A recent cover of Science magazine features a visualization from a long-standing INCITE/OLCF user team’s quest to discover the mechanism behind the explosions of core-collapse supernovas (CCSNs).

The June 1, 2012 issue of Science explores eight unsolved problems in astronomy, including CCSN’s. The phenomenon has been explored by multiple teams on OLCF systems for years, yielding numerous breakthroughs in our quest to understand the origins of our universe.

The visualization is related to a paper the team, led by ORNL’s Tony Mezzacappa, published in Nature in 2008. The Nature paper detailed a possible mechanism to spin up neutron stars to become pulsars, or rotating neutrons stars, which are only derived from CCSNs.  Pulsars are handy tools for astronomers and physicist due to the regular intervals at which they emit radiation towards the Earth.

Previously, researchers had no good explanation for how a slowly rotating star gains speed. The standing accretion shock instability (SASI), a phenomenon that occurs in a stalled supernova shock, provides an explanation for how you get fast rotation even if you don’t have a spinning star to start with, said team member and OLCF staff member Bronson Messer.

According to Messer, “The SASI and, in particular, its possible role in pulsar birth, was really made clear via visualizations such as the one on the cover of Science.”