Nuclear Burning in Accretion Flow of Helium-rich matter onto Compact Objects

TL;DR

This paper studies how nuclear burning affects the steady accretion of helium-rich matter onto compact objects, revealing critical accretion rates that influence flow truncation and incorporating a detailed nuclear reaction network for more accurate modeling.

Contribution

It introduces a detailed nuclear reaction network into accretion flow models, extending previous work on CO-rich matter to helium-rich matter and identifying new critical accretion rates.

Findings

Critical accretion rates for helium-rich matter are identified.

Nuclear burning influences flow truncation in accretion processes.

Revised models confirm previous results and reveal new insights.

Abstract

We investigate the impacts of nuclear burning on the spherically symmetric stationary accretion flow of helium-rich matter on to compact objects. We have already shown the existence of the critical accretion rates for the accretion of CO-rich matter above which the flow truncates in the supersonic region due to nuclear burning in the previous paper \citep{2022ApJ...933...29N}. Here, we show that there are also critical accretion rates for helium-rich matter. While we used empirical formulae for the energy generation rates for carbon burning and oxygen burning without solving the nuclear reaction network in our previous work, we solve a simple nuclear reaction network consisting of 13 elements from $^4$He to $^{56}$Ni to investigate influence of the energy generation from not only triple-$\alpha$ reactions but also the subsequent reactions of synthesized elements. We have also qualitatively confirmed the previous results for CO-rich matter accretion using the revised code with the nuclear reaction network and reported some new findings.