Related papers: ASTRO-H White Paper - White Dwarf
Accreting binary white dwarf systems are among the sources expected to emanate gravitational waves that the Laser Interferometer Space Antenna (LISA) will detect. We investigate how accurately the binary parameters may be measured from LISA…
We present the results of our study of ASASSN-14dx, a previously known but poorly characterised cataclysmic variable (CV). The source was observed as part of an ongoing high-time-resolution photometric survey of CVs, which revealed that, in…
We use multi-epoch spectroscopy of about 4000 white dwarfs in the Sloan Digital Sky Survey to constrain the properties of the Galactic population of binary white dwarf systems and calculate their merger rate. With a Monte Carlo code, we…
We present the first X-ray observations of the 4 Draconis system, consisting of an M3III giant with a hot ultraviolet companion. It has been claimed that the companion is itself an AM Her-type binary system, an identification that places…
Using the results of recent work in shear instabilities in stratified fluids, we show that the resonant interaction between large-scale flows in the accreted H/He envelope of white dwarf stars and interfacial gravity waves can mix with the…
Close pairs of white dwarfs are potential progenitors of Type~Ia supernovae and they are common, with of order 100 -- 300 million in the Galaxy. As such they will be significant, probably dominant, sources of the gravitational waves…
Our recent theoretical work (Townsley and Bildsten 2002) on the thermal state of white dwarfs (WDs) in low mass transfer rate binaries allows us to predict the broadband colors of the binary from those of the WD and companion when the disk…
Novae have been reported as transients for more than two thousand years. Their bright optical outbursts are the result of explosive nuclear burning of gas accreted from a binary companion onto a white dwarf. Novae containing a white dwarf…
Beyond the main sequence solar type stars undergo extensive mass loss, providing an environment where planet and brown dwarf companions interact with the surrounding material. To examine the interaction of substellar mass objects embedded…
Symbiotic stars, which generally comprise a red giant and an accreting white dwarf, are excellent laboratories to understand mass transfer in wide binaries, with application to a wide family of systems. One of the fundamental questions is…
We examine 14 hot white dwarfs for signs of infrared excess using the Spitzer Space Telescope. Twelve of the objects are massive white dwarfs which have been suggested to be the result of binary mergers. The remaining two objects are…
Neutron stars and stellar-mass black holes are the remnants of massive stars, which ended their lives in supernova explosions. These exotic objects can only be studied in relatively rare cases. If they are interacting with close companions…
We present a new model of the population of symbiotic X-ray binaries (SyXBs) that takes into account non-stationary character of quasi-spherical sub-sonic accretion of the red giant's stellar wind onto slowly rotating neutron stars. Updates…
X-ray-emitting symbiotic stars exhibit a variety of spectral shapes classified as $\alpha$, $\beta$, $\gamma$, $\delta$ and $\beta$/$\delta$ types, which have been attributed to different phenomena such as thermonuclear burning on the…
Type Ia supernovae are cosmic distance indicators, and the main source of iron in the Universe, but their formation paths are still debated. Several dozen supersoft X-ray sources, in which a white dwarf accretes hydrogen-rich matter from a…
The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…
Accretion of mass onto a white dwarf (WD) in a binary system can lead to stellar explosions. If a WD accretes from stellar wind of a distant evolved giant in a symbiotic binary, it can undergo occasional outbursts in which it brightens by…
In this paper, we demonstrate ASTRO-H's capability to measure the chemical evolution in the high-z (z <~ 3) universe by observing X-ray afterglows of gamma-ray bursts (GRBs) and distant Blazars. Utilizing these sources as background light…
The masses of compact objects like white dwarfs, neutron stars and black holes are fundamental to astrophysics, but very difficult to measure. We present the results of an analysis of subluminous B (sdB) stars in close binary systems with…
Interacting white dwarf binary star systems, including helium cataclysmic variable (HeCV) systems, are expected to be strong sources of gravitational radiation, and should be detectable by proposed space-based laser interferometer…