Stationary accretion flow with nuclear burning

TL;DR

This paper presents numerical solutions for stationary, spherically symmetric accretion flows with nuclear burning onto neutron stars, revealing two flow types depending on accretion rate and discussing implications for certain supernovae.

Contribution

It introduces a new analysis of accretion flows with nuclear burning, identifying critical accretion rates and flow behaviors relevant to supernova mechanisms.

Findings

Two types of transonic solutions depending on accretion rate.

Critical accretion rate derived as a function of central mass and enthalpy.

Implications for super-Chandrasekhar and type Icn supernovae.

Abstract

We present a series of numerical solutions of spherically symmetric stationary flows with nuclear burning accreted by a neutron star (or black hole). We consider the accretion of matter composed of carbon and oxygen, which mimics the flow after a neutron star is engulfed by a CO star or CO core of a massive star. It is found that there are two types of transonic solutions depending on the accretion rate. The flow with a small accretion rate reaches the center (or the surface of the central object) at supersonic speeds. The other type with a large accretion rate has another sonic point inside the transonic point and the flow truncates at the sonic point. The critical accretion rate dividing these two types is derived as a function of the mass of the central object and the specific enthalpy in the ambient matter. We discuss implications from the solutions for a new mechanism of super-Chandrasekhar type Ia supernovae and type Icn supernovae.