PREPRINT
8F41BAFE-B027-4671-9C42-69BA7047FCFA

# Chandrasekhar-mass white dwarfs are the progenitors of a small fraction of Type Ia supernovae according to nucleosythesis constraints

Eduardo Bravo, Luciano Piersanti, Stéphane Blondin, Inma Domínguez, Oscar Straniero, Sergio Cristallo
arXiv:2209.04020

Submitted on 8 September 2022

## Abstract

The precise progenitor system of type Ia supernovae (SNe Ia), whether it is a white dwarf (WD) close to the Chandrasekhar limit or substantially less massive, has been a matter of debate for decades. Recent research by our group on the accretion and simmering phases preceding the explosion of a massive WD has shown that the central density at thermal runaway lies in the range $\left(3.6-6.3\right)×{10}^{9}$ g cm${}^{-3}$ for reasonable choices of accretion rate onto the WD and progenitor metallicity. In this work, we have computed one-dimensional simulations of the explosion of such WDs, with special emphasis on the chemical composition of the ejecta, which in all cases is extremely rich in neutronized isotopes of chromium (${}^{54}$Cr) and titanium (${}^{50}$Ti). We show that, in order to reconcile such a nucleosynthesis with the isotopic abundances of the Solar System, Chandrasekhar-mass white dwarfs can account for at most 26 per cent of normal-luminosity SNe Ia, or at most 20 per cent of all SNe Ia.

## Preprint

Comment: 5 pages, 1 table, 3 figures; Letter accepted by MNRAS

Subjects: Astrophysics - Solar and Stellar Astrophysics; Astrophysics - High Energy Astrophysical Phenomena