Related papers: Heavy Elements Nucleosynthesis On Accreting White …
Type Ia supernovae (SN Ia) are the most important standard candles for measuring the expansion history of the universe. The thermonuclear explosion of a white dwarf can explain their observed properties, but neither the progenitor systems…
Roughly half of the heavy elements (atomic mass greater than that of iron) are believed to be synthesized in the late evolutionary stages of stars with masses between 0.8 and 8 solar masses. Deep inside the star, nuclei (mainly iron)…
While the high-entropy wind (HEW) of Type II supernovae remains one of the more promising sites for the rapid neutron-capture (r-) process, hydrodynamic simulations have yet to reproduce the astrophysical conditions under which the latter…
Type Ia supernovae (SNe) are believed to be caused by the thermonuclear explosion of a white dwarf (WD), but the nature of the progenitor system(s) is still unclear. Recent theoretical and observational developments have led to renewed…
In the single degenerate (SD) scenario for type Ia supernovae (SNe Ia), a mass-accreting white dwarf is expected to experience a supersoft X-ray source (SSS) phase. However, some recent observations showed that the expected number of the…
Some metal-poor stars have abundance patterns which are midway between the slow (s) and rapid (r) neutron capture processes. We show that the helium shell of a fast rotating massive star experiencing a jet-like explosion undergoes two…
A clear definition of the contribution from the slow neutron-capture process (s process) to the solar abundances between Fe and the Sr-Zr region is a crucial challenge for nuclear astrophysics. Robust s-process predictions are necessary to…
We report abundance estimates for neutron-capture elements, including lead (Pb), and nucleosynthesis models for their origin, in two carbon-rich, very metal-poor stars, LP625-44 and LP706-7. These stars are subgiants whose surface…
As an explosion develops in the collapsed core of a massive star, neutrino emission drives convection in a hot bubble of radiation, nucleons, and pairs just outside a proto-neutron star. Shortly thereafter, neutrinos drive a wind-like…
Observations of metal-poor stars indicate that at least two different nucleosynthesis sites contribute to the production of r-process elements. One site is responsible for the production of light r-process elements Z<~50 while the other…
Massive-star binaries can undergo a phase where one of the two stars expands during its advanced evolutionary stage as a giant and envelops its companion, ejecting the hydrogen envelope and tightening its orbit. Such a common envelope phase…
We model early accretion of light elements, He, C, and O, onto a new-born neutron star using the public stellar evolution code MESA, simulating what may happen during the first few years of its life. We find that, under the appropriate…
The merger of two white dwarfs (WDs) has for many years not been considered as the favoured model for the progenitor system of type Ia supernovae (SNe Ia). But recent years have seen a change of opinion as a number of studies, both…
We analyze temporal evolution of the number of accreting white dwarfs with shell hydrogen burning in semidetached and detached binaries. We consider a stellar system in which star formation lasts for 10 Gyr with a constant rate, as well as…
We revisit a neutrino-driven r-process mechanism in the He shell of a core-collapse supernova, finding that it could succeed in early stars of metallicity < solar/1000, at relatively low temperatures and neutron densities, producing A ~ 130…
We investigate nucleosynthesis inside both a gamma-ray burst accretion disk and a wind launched from an inner region of the disk using one-dimensional models of the disk and wind and a nuclear reaction network. Far from a central black…
Recent observations of Type Ia supernovae (SNe Ia) suggest that some of the progenitor white dwarfs (WDs) had masses up to 2.4-2.8 M_sun, highly exceeding the Chandrasekhar mass limit. We present a new single degenerate (SD) model for SN Ia…
The accretion of hydrogen-rich material onto carbon-oxygen white dwarfs (CO WDs) is crucial for understanding type Ia supernova (SN Ia) from the single-degenerate model, but this process has not been well understood due to the numerical…
Thermonuclear (type Ia) supernovae are explosions in accreting white dwarfs, but the exact scenario leading to these explosions is still unclear. An important step to clarify this point is to understand the behaviour of accreting white…
We study nucleosynthesis in 'hypernovae', i.e., supernovae with very large explosion energies ($ \gsim 10^{52} $ ergs) for both spherical and aspherical explosions. The hypernova yields compared to those of ordinary core-collapse supernovae…