Recurrent Novae: Progenitors of SN Ia?

TL;DR

This study uses 3D hydrodynamical simulations to analyze the accretion processes in the RS Ophiuchi binary system, assessing its potential as a progenitor of Type Ia supernovae.

Contribution

It provides detailed 3D simulation results of wind accretion in RS Oph, highlighting the impact of thermodynamics and wind speed on accretion efficiency and system evolution.

Findings

Higher accretion rates in isothermal scenarios with slow winds.

System separation decreases over time due to mass and angular momentum loss.

RS Oph remains a promising candidate for SN Ia progenitor.

Abstract

We present 3D hydrodynamical simulations of the separated binary RS Ophiuchi (RS Oph), a recurrent nova and potential progenitor of a SN Ia. RS Oph is composed of a red giant (RG) and a white dwarf (WD) whose mass is close to the Chandrasekhar limit. In an isothermal scenario, the WD accrets about 10% of a 20 km/s RG wind by a non-Keplerian accretion disk with strong spiral shocks, and about 2% of a 60 km/s RG wind by what we term a 'turbulent accretion ball'. A significantly larger impact have the thermodynamics. In an adiabatic scenario only about 0.7% of the 20 km/s RG wind is accreted. The rate of change of the system separation due to mass and angular momentum loss out of the system is negative in all three cases studied, but is ten times smaller for a fast RG wind (60 km/s) than for a slow RG wind (20 km/s). The results demonstrate that existing nova models and observed recurrence times fit well together with 3D wind accretion and that RS Oph is one of the most promising systems to become an SN Ia.