paper

Off-centre ignition of sub-Chandrasekhar white dwarfs does not resolve the tension with the observed - relation of type Ia supernovae

arXiv:2410.02849 · doi:10.1093/mnras/stae2770

Abstract

Type Ia supernovae (SNe Ia) are likely the thermonuclear explosions of carbon-oxygen (CO) white-dwarf (WD) stars, but the exact nature of their progenitor systems remains uncertain. Recent studies have suggested that a propagating detonation within a thin helium shell surrounding a sub-Chandrasekhar mass CO core can subsequently trigger a detonation within the core (the double-detonation model, DDM). The resulting explosion resembles a central ignition of a sub-Chandrasekhar mass CO WD (SCD), which is known to be in tension with the observed - relation, where (the -rays' escape time from the ejecta) is positively correlated with (the synthesized Ni mass). SCD predicts an anticorrelation between and , with for luminous () SNe Ia, while the observed is in the range of 35-45 day. In this study, we apply our recently developed numerical scheme to calculate in 2D the impact of off-centre ignition in sub-Chandrasekhar mass CO WD, aiming to better emulate the behaviour expected in the DDM scenario. Our calculations of the - relation, which do not require radiation transfer calculations, achieve convergence to within a few per cent with a numerical resolution of . We find that the results only slightly depend on the ignition location, mirroring the SCD model, and consequently, the discrepancy with the observed - relation remains unresolved.

12 pages, 8 figures. Published on MNRAS

References in corpus (20)

Cited by in corpus (1)