Related papers: Explosive Nucleosynthesis in Hypernovae
Important clues to the chemical and dynamical history of elliptical galaxies are encoded in the abundances of heavy elements in the X-ray emitting plasma. We derive the hot ISM abundance pattern in inner and outer regions of NGC 4472 from…
New abundances of N, O, Na, Mg, Si, Ca, Sc, Ti, Cr, Fe, Sr, Zr, and Ba are presented for 10 A-type supergiants in the SMC, plus upper limits for C. In interpreting the CNO results for constraints on stellar evolution theories, careful…
We demonstrate that rapid expansion of the shocked surface layers of an O-Ne-Mg core following its collapse can result in r-process nucleosynthesis. As the supernova shock accelerates through these layers, it makes them expand so rapidly…
Nucleosynthesis in the s process takes place in the He burning layers of low mass AGB stars and during the He and C burning phases of massive stars. The s process contributes about half of the element abundances between Cu and Bi in solar…
Light element synthesis in supernovae through neutrino-nucleus interactions, i.e., the nu-process, is affected by neutrino oscillations in the supernova environment. There is a resonance of 13-mixing in the O/C layer, which increases the…
We present a new analysis of the abundances observed in extremely metal poor stars based on both a new generation of theoretical presupernova models and explosions of zero metallicity massive stars and a new abundance analysis of an…
The first metal enrichment in the universe was made by supernova (SN) explosions of population (Pop) III stars. The trace remains in abundance patterns of extremely metal-poor (EMP) stars. We investigate the properties of nucleosynthesis in…
The spectra of several galaxies, including extremely metal-poor galaxies (EMPGs) from the EMPRESS survey, have shown that the abundances of some Si-group elements differ from "spherical" explosion models of massive stars. This leads to the…
Previous work on the abundances of C, O, Na, Mg, Si, Ca, Ti, Cr, Mn, Fe, Ni, Cu, and Zn in low-alpha (accreted) and high-alpha (in situ born) halo stars is extended to include the abundances of Sc, V, and Co, enabling us to study the…
We investigated r-process nucleosynthesis in magneto-rotational supernovae, based on a new explosion mechanism induced by the magneto-rotational instability. A series of axisymmetric magneto-hydrodynamical simulations with detailed…
Hypernovae powered by magnetic jets launched from the surface of rapidly rotating millisecond magnetars are one of the leading models to explain broad-lined Type Ic supernovae (SNe Ic-BL), and have been implicated as an important source of…
We present preliminary results of stellar structure and nucleosynthesis calculations for some early stars. The study (still in progress) seeks to explore the expected chemical signatures of second generation low- and intermediate-mass stars…
The Milky Way bulge is an important tracer of the early formation and chemical enrichment of the Galaxy. The abundances of different iron-peak elements in field bulge stars can give information on the nucleosynthesis processes that took…
The production of heavy elements is one of the main by-products of the explosive end of massive stars. A long sought goal is finding differentiated patterns in the nucleosynthesis yields, which could permit identifying a number of…
There is compelling evidence that the peak brightness of a Type Ia supernova is affected by the electron fraction Ye at the time of the explosion. The electron fraction is set by the aboriginal composition of the white dwarf and the…
Recently, measurements of abundances in extremely metal poor (EMP) stars have brought new constraints on stellar evolution models. In an attempt to explain the origin of the abundances observed, we computed pre--supernova evolution models,…
The nucleosynthesis yields from neutrino-induced spallation of 4He are calculated in case of penetration of some 4He into the carbon-oxygen-neon shell. The neutrino contribution to creation of the weak r-process component becomes noticeable…
Preliminary results of a new set of stellar evolution and nucleosynthesis calculations for massive stars are presented. These results were obtained with an extended reaction network up to Bi. The discussion focuses on the importance of…
The death of massive stars is shrouded in many mysteries. One of them is the mechanism that overturns the collapse of the degenerate iron core into an explosion, a process that determines the supernova explosion energy, properties of the…
When binary systems of neutron stars merge, a very small fraction of their rest mass is ejected, either dynamically or secularly. This material is neutron-rich and its nucleosynthesis could provide the astrophysical site for the production…