676 research outputs found
Recurrent novae and long-term evolution of mass-accreting white dwarfs -- toward the accurate mass retention efficiency
The mass growth rate of mass-accreting white dwarfs (WDs) is a key factor in
binary evolution scenarios toward Type Ia supernovae. Many authors have
reported very different WD mass increasing rates. In this review, we clarify
the reasons for such divergence, some of which come from a lack of numerical
techniques, usage of old opacities, different assumptions for binary
configurations, inadequate initial conditions, and unrealistic mass-loss
mechanisms. We emphasize that these assumptions should be carefully chosen in
calculating the long-term evolution of accreting WDs. Importantly, the
mass-loss mechanism is the key process determining the mass retention
efficiency: the best approach involves correctly incorporating the optically
thick wind because it is supported by the multiwavelength light curves of
novae.Comment: 23 pages, 8 figures. Figure 7 is replaced. Several points of
discussion are added. Submitted versio
Towards the Super Yang-Mills Theory on the Lattice
We present an entirely new approach towards a realization of the
supersymmetric Yang-Mills theory on the lattice. The action consists of the
staggered fermion and the plaquette variables distributed in the Euclidean
space with a particular pattern. The system is shown to have fermionic
symmetries relating the fermion and the link variables.Comment: 12 pages, 3 figure
A helium nova in the Large Magellanic Cloud -- the faint supersoft X-ray source [HP99]159
We propose a helium nova model for the Large Magellanic Cloud (LMC) supersoft
X-ray source (SSS) [HP99]159. This object has long been detected as a faint and
persistent SSS for about 30 years, and recently been interpreted to be a source
of steady helium-shell burning, because no hydrogen lines are observed. We find
that the object can also be interpreted as in a decaying phase of a helium
nova. The helium nova is slowly decaying toward the quiescent phase, during
which the observed temperature, luminosity, and SSS lifetime (
years) are consistent with a massive white dwarf model of 1.2 .
If it is the case, this is the second discovery of a helium nova outburst after
V445 Pup in our Galaxy and also the first identified helium nova in the LMC. We
also discuss the nature of the companion helium star in relation to Type Ia
supernova progenitors.Comment: 4 pages, 4 figures, accepted in MNRAS (Letters
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