Related papers: Reconstructing the evolution of double helium whit…
The masses of the white dwarfs in a binary carry information about previous mass-transfer phases. The core mass -- radius relation of low-mass giants gives the size of the progenitor of a helium white dwarf at the moment it last filled its…
We determine the possible masses and radii of the progenitors of white dwarfs in binaries from fits to detailed stellar evolution models and use these to reconstruct the mass-transfer phase in which the white dwarf was formed. We confirm…
We investigate the formation of the ten double-lined double white dwarfs that have been observed so far. A detailed stellar evolution code is used to calculate grids of single-star and binary models and we use these to reconstruct possible…
We describe the evolution of double degenerate binary systems, consisting of components obeying the zero temperature mass radius relationship for white dwarf stars, from the onset of mass transfer to one of several possible outcomes…
Eclipsing close double white dwarf (WD) systems provide a unique opportunity to directly constrain hydrogen-envelope retention and test common-envelope (CE) evolution in low-mass stars, since they allow precise determinations of stellar…
We perform hydrodynamic simulations of mass transfer in binaries that contain a white dwarf and a neutron star (WD-NS binaries), and measure the specific angular momentum of material lost from the binary in disc winds. By incorporating our…
The evolution of low mass (M < 2.5 Msun) binaries through the common envelope phase has been studied for systems in which one member is on its first ascent of the red giant branch. Three-dimensional hydrodynamical simulations have been…
Although several dozen double white dwarfs (DWDs) have been observed, for many the exact nature of the evolutionary channel(s) by which they form remains uncertain. The canonical explanation calls for the progenitor binary system to undergo…
We present a numerical study of the mass transfer dynamics prior to the gravitational wave-driven merger of a double white dwarf system. Recently, there has been some discussion about the dynamics of these last stages, different methods…
We present a numerical method for the study of double white dwarf (DWD) binary systems at the onset of super-Eddington mass transfer. We incorporate the physics of ideal inviscid hydrodynamical flow, Newtonian self-gravity, and radiation…
The new-found prevalence of extremely low mass (ELM, Mhe<0.2 Msun) helium white dwarfs (WDs) in tight binaries with more massive WDs has raised our interest in understanding the nature of their mass transfer. Possessing small (Menv~1e-3…
Tight binaries of helium white dwarfs (He WDs) orbiting millisecond pulsars (MSPs) will eventually "merge" due to gravitational damping of the orbit. The outcome has been predicted to be the production of long-lived ultra-compact X-ray…
We present seven evolutionary tracks for low-mass white dwarfs with helium cores, ranging in mass from 0.179 to 0.414 Msol. We generated the pre-white dwarf models from a 1 Msol sequence extending up to the tip of its red-giant branch by…
One class of compact binaries of special interest is that of double white dwarfs (DWDs). For many of these systems, the exact nature of the evolutionary channels by which they form remains uncertain. The canonical explanation calls for the…
Most close double helium white dwarfs will merge within a Hubble time due to orbital decay by gravitational-wave radiation. However, a significant fraction with low mass ratios will survive for a long time as a consequence of stable mass…
Common envelope (CE) evolution, which is crucial in creating short period binaries and associated astrophysical events, can be constrained by reverse modeling of such binaries' formation histories. Through analysis of a sample of…
We study the angular momentum evolution of binaries containing two white dwarfs which merge and become cool helium-rich supergiants. Our object is to compare predicted rotation velocities with observations of highly evolved stars believed…
The white dwarf mass distribution has been studied primarily at two extremes: objects that presumably evolved as single stars and members of close binaries that likely underwent substantial interaction. This work considers the intermediate…
Massive stars are usually found in binaries, and binaries with periods less than 10 days may have a preference for near equal component masses. In this paper we investigate the evolution of these binaries all the way to contact and the…
The evolution of binaries consisting of evolved main sequence stars (1 < M_d/Msun < 3.5) with white dwarf companions (0.7 < M_wd/Msun < 1.2) is investigated through the thermal mass transfer phase. Taking into account the stabilizing effect…