Related papers: Boron Synthesis in Type Ic Supernovae
We investigate a possible nucleosynthetic signature of highly energetic explosions of C-O cores ("hypernovae," HNe) which might be associated with gamma-ray bursts (GRBs). We note that the direct impact of C- and O-enriched hypernova ejecta…
The neutrino process ($\nu$-process) for the production of 7Li and 11B in core-collapse supernovae (SNe) is extensively investigated. Initial abundances of s-nuclei and other physical conditions are derived from an updated calculation of…
We review the existing set of optical/UV/IR observations of Supernova 1993J, concentrating heavily on optical data because these are by far the most plentiful. Some results from theoretical modeling of the observations are also discussed.…
The light elements beryllium (Be; $Z=4$) and boron (B; $Z=5$) are mainly produced by spallation reactions between cosmic rays and carbon (C; $Z=6$), nitrogen (N; $Z=7$), and oxygen (O; $Z=8$) nuclei. Only traces of Be or B would have been…
We report the first detection of a credible progenitor system for a Type Ic supernova (SN Ic), SN 2017ein. We present spectra and photometry of the SN, finding it to be similar to carbon-rich, low-luminosity SNe Ic. Using a post-explosion…
We study explosion characteristics of ultra-stripped supernovae (SNe), which are candidates of SNe generating binary neutron stars (NSs). As a first step, we perform stellar evolutionary simulations of bare carbon-oxygen cores of mass from…
Core-collapse supernovae are the first polluters of heavy elements in the galactic history. As such, it is important to study the nuclear compositions of their ejecta, and understand their dependence on the progenitor structure (e.g., mass,…
In preparation for a set of hydrodynamical simulations of core-collapse supernovae and protoneutron star winds, we investigate the rates of production and thermalization of $\nu_\mu$ and $\nu_\tau$ neutrinos in dense nuclear matter.…
I briefly describe the Lick Observatory Supernova Search with the 0.76-m Katzman Automatic Imaging Telescope. I then present an overview of optical observations of Type II, IIb, Ib, and Ic supernovae (SNe), all of which are thought to arise…
In the standard supernova picture, type Ib/c and type II supernovae are powered by the potential energy released in the collapse of the core of a massive star. In studying supernovae, we primarily focus on the ejecta that makes it beyond…
Light element nucleosynthesis is an important chapter of nuclear astrophysics. Specifically, the rare and fragile light nuclei Lithium, Beryllium and Boron (LiBeB) are not generated in the normal course of stellar nucleosynthesis (except…
We reconsider the model of neutrino production during the 'bright phase', first suggested in 1977, in the light of modern understanding of the role of Pop III stars and acceleration of particles in supernova shocks. We concentrate on the…
We present results from an ongoing survey of the infrared emission lines [Kr III] 2.199 and [Se IV] 2.287 micron in Galactic planetary nebulae (PNe). Krypton and selenium may be produced by slow neutron-capture nucleosynthesis (the…
Knowledge of the progenitors of core-collapse supernovae is a fundamental component in understanding the explosions. The recent progress in finding such stars is reviewed. The minimum initial mass that can produce a supernova has converged…
SN 2007bi is an extremely luminous Type Ic supernova. This supernova is thought to be evolved from a very massive star, and two possibilities have been proposed for the explosion mechanism. One possibility is a pair-instability supernova…
We discuss the properties of the progenitors of core collapse SNe, as they can be deduced from rotating stellar models of single stars. The type of the SN progenitor was determined from the surface abundances at the pre-SN stage. The type…
Nitrogen is produced by CNO-cycling in massive stars, and can be ejected in significant amounts in supernova explosions. While in H-rich SNe, its [\ion{N}{II}] 6548, 6583 emission becomes obscured by strong H$\alpha$, in explosions of He…
The non-local thermodynamic equilibrium (NLTE) line formation of neutral boron in the atmospheres of cool stars are investigated. Our results confirm that NLTE effects for the B I resonance lines, which are due to a combination of…
Core-collapse supernovae are a promising potential high-energy neutrino source class. We test for correlation between seven years of IceCube neutrino data and a catalog containing more than 1000 core-collapse supernovae of types IIn and IIP…
Core collapse supernovae are the leading actor in the story of the cosmic origin of the chemical elements. Existing models, which generally assume spherical symmetry and parameterize the explosion, have been able to broadly replicate the…