3D Heat Transport, Burning, and Evolution

CI: – Dr. A. Heger

Type I X-ray bursts on the surface of accreting neutron stars are the most frequently observed thermonuclear explosions in the universe. Understanding these explosions and the systems that produce them gives us insight into fundamental physics such as the dense equation of state, nuclear reactions we cannot replicate on Earth, and the influence of strong magnetic and gravitational fields. X-ray bursts have been comprehensively modelled in 1D since the 1970s, but multi-D models have not been feasible due to computational limitations. We have developed the first multi-dimensional time-dependent implicit model of the heating, ignition and burning of accreted fuel that powers such X-ray bursts on the surface of accreting neutron stars. We have already created the framework for this code but require assistance to port the code for use with GPUs and HPC clusters, in particular the replacement of the Numpy sparse matrix solver (single interface/call) by a GPU/MPI version optimised to our matrix structure. Although this code was developed for modelling the ignition conditions of X-ray bursts, the general nature as a multi-D heat transport code allows a much wider range of applications both in the astrophysical community, such as novae and Type Ia supernovae, as well as planetary sciences.