Sensitivity of He Flames in X-ray Bursts to Nuclear Physics

TL;DR

This study uses 2D hydrodynamic simulations to explore how nuclear physics influences helium flame propagation in X-ray bursts, revealing significant effects from nuclear reactions and plasma screening routines.

Contribution

It demonstrates the impact of specific nuclear reactions and plasma screening methods on flame dynamics in X-ray bursts using advanced simulation techniques.

Findings

Enhanced energy generation affects flame acceleration.

Plasma screening routines influence flame propagation.

Simplified-SDC improves hydrodynamics and reaction coupling.

Abstract

Through the use of axisymmetric 2D hydrodynamic simulations, we further investigate laterally propagating flames in X-ray bursts (XRBs). Our aim is to understand the sensitivity of a propagating helium flame to different nuclear physics. Using the Castro simulation code, we confirm the phenomenon of enhanced energy generation shortly after a flame is established after by adding ${}^{12}$C(p, ${\gamma}$)${}^{13}$N(${\alpha}$, p)${}^{16}$O to the network, in agreement with the past literature. This sudden outburst of energy leads to a short accelerating phase, causing a drastic alteration in the overall dynamics of the flame in XRBs. Furthermore, we investigate the influence of different plasma screening routines on the propagation of the XRB flame. We finally examine the performance of simplified-SDC, a novel approach to hydrodynamics and reaction coupling incorporated in Castro, as an alternative to operator-splitting.