Presentation #309.03 in the session “Supernovae 1”.
Recent theoretical work compellingly argues that a substantial fraction of type Ia supernova (SNe Ia) events are explosions of near-Chandrasekhar mass (MCh) white dwarfs (WDs). As much as half of the total SNe Ia rate is required to come from these sources in order to produce a solar abundance of 55Mn. Yet, numerous observations place tight constraints on the prevalence of near-MCh SNe Ia events produced through the canonical single-degenerate (SD) channel. In this talk, I propose that near-MCh SNe Ia are produced primarily not through the SD channel, as is widely believed, but instead through the double degenerate channel of merging WDs. I will demonstrate that the magnetohydrodynamical processes in merging WD systems naturally lead to a substantial population within a narrow mass range close to MCh, and argue that the resulting mergers lead to central ignition and subsequent SNe Ia. I will also present the full multidimensional hydrodynamical simulation, nucleosynthesis, and synthetic spectra resulting from such an event.