Mechanisms of core-collapse supernovae & simulation results from the CHIMERA code

Unraveling the mechanism for core-collapse supernova explosions is an outstanding computational challenge and the problem remains essentially unsolved despite more than four decades of effort. However, much progress in realistic modeling has occurred recently through the availability of midti-teraflop machines and the increasing sophistication of supernova codes. These improvements have led to some key insights which may clarify the picture in the not too distant future. Here we briefly review the current status of the three explosion mechanisms (acoustic, MHD, and neutrino heating) that are currently under active investigation, concentrating on the neutrino heating mechanism as the one most Ukely responsible for producing explosions from progenitors in the mass range ̃ 10 to ̃ 25 M. We then briefly describe the CHIMERA code, a supernova code we have developed to simidate core-coUapse supernovae in 1, 2, and 3 spatial dimensions. We finaUy describe the residts of an ongoing siute of 2D simidations initiated from a 12, 15, 20, and 25 MQ progenitor. These have all exhibited explosions and are currently in the expanding phase with the shock at between 5,000 and 10,000 km. We finally very briefly describe an ongoing simulation in 3 spatial dimensions initiated from the 15 MQ progenitor.