Related papers: Toward Resolved Simulations of Burning Fronts in T…
We explore the early evolution of flame ignition and spreading on the surface of a neutron star in three-dimensions, in the context of X-ray bursts. We look at the nucleosynthesis and morphology of the burning front and compare to…
We investigate the structure of laterally-propagating flames through the highly-stratified burning layer in an X-ray burst. Two-dimensional hydrodynamics simulations of flame propagation are performed through a rotating plane-parallel…
Type-I X-ray bursts arise from unstable thermonuclear burning of accreted fuel on the surface of neutron stars. In this chapter we review the fundamental physics of the burning processes, and summarise the observational, numerical, and…
X-ray bursts are the thermonuclear runaway of a mixed H/He layer on the surface of a neutron star. Observations suggest that the burning begins locally and spreads across the surface of the star as a flame. Recent multidimensional work has…
Gamma-ray bursts are a complex, non-linear system that evolves very rapidly through stages of vastly different conditions. They evolve from scales of few hundred kilometers where they are very dense and hot to cold and tenuous on scales of…
We continue to investigate two-dimensional laterally propagating flames in type I X-ray bursts using fully compressible hydrodynamics simulations. In the current study we relax previous approximations where we artificially boosted the…
After decades of one-dimensional nucleosynthesis calculations, the growth of computational resources has meanwhile reached a level, which for the first time allows astrophysicists to consider performing routinely realistic multidimensional…
Thermonuclear X-ray bursts from the surface of accreting neutron stars are the most common astrophysical explosions in our galaxy. They provide a unique window into the physics of neutron stars, the physics of matter under extreme…
Our understanding of stars and their fates is based on coupling observations to theoretical models. Unlike laboratory physicists, we cannot perform experiments on stars, but rather must patiently take what nature allows us to observe.…
In low-mass X-ray binaries, the accretion of stellar material onto a neutron star can fuel unstable thermonuclear flashes known as Type I X-ray bursts. Simulating these events using computational models can provide valuable information…
We investigate the properties of mixed H/He flames in X-ray bursts using 2D hydrodynamic simulations. We find that as the initial hydrogen abundance of the atmosphere increases, the flame is less energetic and propagates slower. The…
High performance computing numerical simulations are today one of the more effective instruments to implement and study new theoretical models, and they are mandatory during the preparatory phase and operational phase of any scientific…
The past decade and a half has seen many interesting new developments in X-ray burst research, both observationally and theoretically. New phenomena were discovered, such as burst oscillations and superbursts, and new regimes of…
The numerical simulation of turbulence in stars has led to a rich set of possibilities regarding stellar pulsations, asteroseismology, thermonuclear yields, and formation of neutron stars and black holes. The breaking of symmetry by…
We perform the first detailed three-dimensional simulation of low Mach number convection preceding thermonuclear ignition in a mixed H/He X-ray burst. Our simulations include a moderate-sized, approximate network that captures hydrogen and…
Numerical models allow the investigation of phenomena that cannot exist in a laboratory. Computational simulations are therefore essential for advancing our knowledge of astrophysics, however, the very nature of simulation requires making…
X-ray bursts are thermonuclear flashes on the surface of accreting neutron stars and reliable burst models are needed to interpret observations in terms of properties of the neutron star and the binary system. We investigate the dependence…
We review recent advances in the numerical modeling of turbulent flows and star formation. An overview of the most widely used simulation codes and their core capabilities is provided. We then examine methods for achieving the…
In this paper I review the motivation and current status of modeling of plasmas exposed to strong radiation fields, as it applies to the study of cosmic X-ray sources. This includes some of the astrophysical issues which can be addressed,…
We describe observational evidence and theoretical calculations which support the high velocity neutron star model of gamma-ray bursts. We estimate the energetic requirements in this model, and discuss possible energy sources. we also…