Related papers: Surface Detonations in Double Degenerate Binary Sy…
For many binary mixtures, the three-phase solid-liquid-vapor equilibrium curve has intermediate pressures that are higher than the pressure at the two pure triple points. This curve shape results in a negative slope in the high-temperature…
Stellar evolution models predict the existence of hybrid white dwarfs (WDs) with a carbon-oxygen core surrounded by an oxygen-neon mantle. Being born with masses ~1.1 Msun, hybrid WDs in a binary system may easily approach the Chandrasekhar…
Equilibrium fluid configurations for close binary systems can become {\em globally unstable\/}. Instabilities arise from the strong tidal interaction between the two components, which tends to make the effective two-body potential governing…
Most previous efforts for hydrodynamic studies on detonation in the context of Type Ia supernovae did not take into account the scale of the cellular structure for a criterion in initiation, propagation, quenching, and the resolution…
Type Ia supernovae (SNe) are believed to be thermonuclear explosions of white dwarf (WD) stars, but their progenitor systems and explosion mechanisms are still unclear. Here we focus on double degenerate systems, where two WDs are…
We describe observational evidence for a new kind of interacting-binary-star outburst that involves both an accretion instability and an increase in thermonuclear shell burning on the surface of an accreting white dwarf. We refer to this…
We present a brief summary of the Single Degenerate Scenario for the progenitors of Type Ia Supernovae in which it is assumed that a low mass carbon-oxygen white dwarf is growing in mass as a result of accretion from a secondary star in a…
The accretion of hydrogen-rich matter onto C/O and O/Ne white dwarfs in binary systems leads to unstable thermonuclear ignition of the accreted envelope, triggering a convective thermonuclear runaway and a subsequent classical, recurrent,…
We construct a two-zone model to describe H and He burning on the surface of an accreting neutron star and use it to study the triggering of type I X-ray bursts. Although highly simplified, the model reproduces all of the bursting regimes…
Thermonuclear, or Type Ia supernovae (SNe Ia), originate from the explosion of carbon--oxygen white dwarfs, and serve as standardizable cosmological candles. However, despite their importance, the nature of the progenitor systems that give…
We study the initiation of thermonuclear detonations in tidally disrupted white dwarf stars by intermediate-mass ($10^3 M_\odot$) black holes. The length scales required to resolve the initiation mechanism are not easily reached in…
The dynamics of helium shell convection driven by nuclear burning establish the conditions for runaway in the sub-Chandrasekhar mass, double detonation model for Type Ia supernovae, as well as for a variety of other explosive phenomena. We…
In a binary fluid mixture, the concentration gradient of a heavier molecular solute leads to a diffusive flux of solvent and solute to achieve thermodynamic equilibrium. If the solute concentration decreases with height, the system is…
We have carried out 200,000 N-body simulations of three identical stellar embryos with masses from a Chabrier IMF and embedded in a molecular core. The bodies are initially non-hierarchical and undergo chaotic motions, while accreting using…
We study mass ejection from accretion disks formed in the merger of a white dwarf with a neutron star or black hole. These disks are mostly radiatively-inefficient and support nuclear fusion reactions, with ensuing outflows and…
Compact binary white dwarfs (WDs) undergoing orbital decay due to gravitational radiation can experience significant tidal heating prior to merger. In these WDs, the dominant tidal effect involves the excitation of outgoing gravity waves in…
Some binary systems composed of a white dwarf (WD) and a hot subdwarf (sdB) helium star will make contact within the helium burning lifetime of the sdB star. The accreted helium on the WD inevitably undergoes a thermonuclear instability,…
We investigate the evolutionary properties of AM~CVn stars with massive white dwarf donors and accretors. As a representative of them we consider a binary initially composed by a 0.30 M$_\odot$, He WD and a 1.02 M$_\odot$, CO WD. We…
Upon formation, degenerate He core white dwarfs are surrounded by a radiative H-rich layer primarily supported by ideal gas pressure. In this Letter, we examine the effect of this H-rich layer on mass transfer in He+C/O double white dwarf…
Binary systems of two carbon-oxygen white dwarfs are one of the most promising candidates for the progenitor systems of Type Ia supernovae. Violent mergers, where the primary white dwarf ignites when the secondary white dwarf smashes onto…