Physics of Thermonuclear Explosions: Magnetic Field Effects on Deflagration Fronts and Observable Consequences

Abstract

Abstract We present a study of the influence of magnetic field strength and morphology in Type Ia supernovae and their late-time light curves and spectra. In order to both capture self-consistent magnetic field topologies and evolve our models to late times, a two-stage approach is taken. We study the early deflagration phase (∼1 s) using a variety of magnetic field strengths and find that the topology of the field is set by the burning, independent of the initial strength. We study late-time (∼1000 days) light curves and spectra with a variety of magnetic field topologies and infer magnetic field strengths from observed supernovae. Lower limits are found to be 106 G. This is determined by the escape, or lack thereof, of positrons that are tied to the magnetic field. The first stage employs 3D MHD and a local burning approximation and uses the code Enzo. The second stage employs a hybrid approach, with 3D radiation and positron transport and spherical hydrodynamics. The second stage uses the code HYDRA. In our models, magnetic field amplification remains small during the early deflagration phase. Late-time spectra bear the imprint of both magnetic field strength and morphology. Implications for alternative explosion scenarios are discussed.