Effects of tangential velocity in the reactive relativistic Riemann problem
arXiv:1806.07301 · doi:10.3847/1538-4357/ab40ab
Abstract
Type I X-ray bursts are thermonuclear burning events which occur on the surfaces of accreting neutron stars. Burning begins in a localised spot in the star's ocean layer before propagating across the entire surface as a deflagration. On the scale of the entire star, the burning front can be thought of as discontinuity. To model this, we investigated the reactive Riemann problem for relativistic deflagrations and detonations and developed a numerical solver. Unlike for the Newtonian Riemann problem, where only the velocity perpendicular to the interface is relevant, in the relativistic case the tangential velocity becomes coupled through the Lorentz factor and can alter the waves present in the solution. We investigated whether a fast tangential velocity may be able to cause a deflagration wave to transition to a detonation. We found that such a transition is possible, but only for tangential velocities that are a significant fraction of the speed of light or for systems already on the verge of transitioning. Consequently, it is highly unlikely that this transition would occur for a burning front in a neutron star ocean without significant contributions from additional multidimensional effects.
arXiv comment16 pages, 10 figures, Accepted for publication in ApJ
References in corpus (11)
- Masses, Radii, and Equation of State of Neutron Stars
- Measuring the neutron star equation of state using X-ray timing
- Flares in long and short Gamma-Ray Bursts: a common origin in a hyperaccreting accretion disk
- Propagation of thermonuclear flames on rapidly rotating neutron stars: extreme weather during type I X-ray bursts
- Rotational Evolution During Type I X-Ray Bursts
- The exact solution of the Riemann problem with non-zero tangential velocities in relativistic hydrodynamics
- Thermonuclear X-ray Bursts: Theory vs. Observations
- Flame Propagation on the Surfaces of Rapidly Rotating Neutron Stars during Type I X-ray Bursts
- New Relativistic Effects in the Dynamics of Nonlinear Hydrodynamical Waves
- Multidimensional Modeling of Type I X-ray Bursts. I. Two-Dimensional Convection Prior to the Outburst of a Pure Helium Accretor
- Rankine-Hugoniot Relations in Relativistic Combustion Waves