Possible Contribution of Magnetized White Dwarf Binaries to Type Ia Supernova Populations

TL;DR

This study explores how strongly magnetized white dwarf binaries in the single-degenerate channel could significantly contribute to Type Ia supernovae, with unique observational signatures and a roughly proportional rate to classical models.

Contribution

It introduces binary population synthesis simulations including magnetized white dwarfs, revealing their comparable contribution to classical non-magnetized systems in producing SNe Ia.

Findings

Magnetized WD systems contribute at least 30% to SNe Ia.

Delay time distribution follows a t^{-1} power-law.

Magnetized systems may produce SNe Ia with different observational properties.

Abstract

The evolution of an accreting white dwarf (WD) with strong magnetic field toward a type Ia supernova (SN Ia) may differ from the classical single-degenerate (SD) channel. In this paper, we perform binary population synthesis (BPS) simulations for the SD channel with a main-sequence (MS) companion, including the strongly magnetized WD accretion. Under a reasonable assumption that the fraction of such systems is $\sim 15$%, the resulting delay time distribution (DTD) roughly follows the $t^{-1}$ power-law distribution. Within the (WD/MS) SD channel, the contribution from the highly magnetized WD is estimated to be comparable to that from the classical, non-magnetized WD channel. The contribution of the SD channel toward SNe Ia can be at least $\sim 30$% among the whole SN Ia population. We suggest that the SNe Ia resulting from the highly-magnetized WD systems would not share observational properties expected for the classical SD channel; for every (potentially peculiar) SN observationally associated with the SD channel, we expect a comparable number of the `hidden' SD population in the normal class.