Abstract
Type Ia supernovae (SNe Ia) are crucial because of their role as standardizable candles in cosmology. Yet, the nature of their progenitor is elusive. For decades, the near-Chandrasekhar mass (near-MCh) single-degenerate (SD) channel, consisting of a system of a white dwarf(WD) accreting mass from a main sequence or red giant star, was considered the leading channel for SNe Ia. However, recent observational evidence has placed tight constraints on the pervasiveness of the SD channel. Further, studies have shown that a substantial fraction of near-MCh events, nearly half of the total SNe Ia rate, are required to produce the solar abundance of manganese. Thus, motivated by the observations, we propose a viable mechanism for a near-MCh event from a binary system of WDs, known as the double-degenerate(DD) channel. To explore the observational consequences of such a near-MCh DD event, I have carried out multidimensional hydrodynamical simulations using the adaptive mesh refinement code FLASH, followed by post-processing using nuclear reaction network and radiation transport codes to obtain nucleosynthetic yields and spectra. The synthetic spectra are then compared against actual supernovae events and classified. The proposed mechanism naturally solves numerous shortcomings of the SD channel, such as the delay time distribution, and the absence of both stellar companion and ex-companions. Our results also show that DD near-MCh events could account for a significant fraction of SNe Ia events and could help explain the solar abundance of manganese.