  In this work an astrophysical simulation code, XFLAT, is developed to study
neutrino oscillations in supernovae. XFLAT is designed to utilize multiple
levels of parallelism through MPI, OpenMP, and SIMD instructions
(vectorization). It can run on both the CPU and the Xeon Phi co-processor, the
latter of which is based on the Intel Many Integrated Core Architecture (MIC).
The performance of XFLAT on configurations and scenarios has been analyzed. In
addition, the impact of I/O and the multi-node configuration on the Xeon
Phi-equipped heterogeneous supercomputers such as Stampede at the Texas
Advanced Computing Center (TACC) was investigated.
