THREE-DIMENSIONAL SIMULATIONS OF PURE DEFLAGRATION MODELS FOR THERMONUCLEAR SUPERNOVAE

Abstract

We present a systematic study of the pure deflagration model of Type Ia\nsupernovae using three-dimensional, high-resolution, full-star hydrodynamical\nsimulations, nucleosynthetic yields calculated using Lagrangian tracer\nparticles, and light curves calculated using radiation transport. We evaluate\nthe simulations by comparing their predicted light curves with many observed\nSNe Ia using the SALT2 data-driven model and find that the simulations may\ncorrespond to under-luminous SNe Iax. We explore the effects of the initial\nconditions on our results by varying the number of randomly selected ignition\npoints from 63 to 3500, and the radius of the centered sphere they are confined\nin from 128 to 384 km. We find that the rate of nuclear burning depends on the\nnumber of ignition points at early times, the density of ignition points at\nintermediate times, and the radius of the confining sphere at late times. The\nresults depend primarily on the number of ignition points, but we do not expect\nthis to be the case in general. The simulations with few ignition points\nrelease more nuclear energy $E_{\\mathrm{nuc}}$, have larger kinetic energies\n$E_{\\mathrm{K}}$, and produce more $^{56}$Ni than those with many ignition\npoints, and differ in the distribution of $^{56}$Ni, Si, and C/O in the ejecta.\nFor these reasons, the simulations with few ignition points exhibit higher peak\nB-band absolute magnitudes $M_\\mathrm{B}$ and light curves that rise and\ndecline more quickly; their $M_\\mathrm{B}$ and light curves resemble those of\nunder-luminous SNe Iax, while those for simulations with many ignition points\nare not.\n