Physical properties of laminar helium deflagrations

The physical properties of laminar deflagrations propagating through helium-rich compositions are determined for a wide range of temperatures and densities. The speeds, thermal widths, reactive widths, density contrasts, critical temperatures, and trigger masses are analyzed, along with their sensitivity to the input thermal transport coefficients, nuclear reaction rates, nuclear reaction network employed, and equation of state. A simple fitting formula of modest accuracy for the laminar flame speed is given, as well as detailed tables that list all of the physical properties. These physical properties may be incorporated into hydrodynamic programs as subgrid models for flame-tracking algorithms, and have applications toward models of X-ray bursts and the thin-shell helium flash of intermediate-mass stars.