Supernovae

In order to test the performance of the parallel code in a practical application with velocity fields we calculated a supernova atmosphere model with parameters typical for a Type Ia supernova explosion. The total number of wavelength points = 48397, the total number of levels treated in NLTE = 3752, and the total number of primary NLTE transitions = 16594, the number of secondary NLTE transitions = 184943, and the number of LTE lines=2346474. Fig. 3a displays the wall-clock time for a single model iteration as a function of processors and Fig. 3b shows the speed-up, which in agreement with our above results scales roughly as $N_{\rm node}/2$. While this is significantly below the theoretical maximum of $N_{\rm node}$ scaling, it is a significant speed-up for practical applications.