Related papers: Explosive Nucleosynthesis from GRB and Hypernova P…
The central engine of short gamma-ray bursts (sGRBs) is hidden from direct view, operating at a scale much smaller than that probed by the emitted radiation. Thus we must infer its origin not only with respect to the formation of the {\it…
Black holes generate collimated, relativistic jets which have been observed in gamma-ray bursts (GRBs), microquasars, and at the center of some galaxies (active galactic nuclei; AGN). How jet physics scales from stellar black holes in GRBs…
Short Gamma-Ray Bursts (GRBs) are explosions of cosmic origin believed to be associated with the merger of two compact objects, either two neutron stars, or a neutron star and a black hole. The presence of at least one neutron star has long…
We study the collapse of rapidly rotating supermassive stars that may have formed in the early Universe. By self-consistently simulating the dynamics from the onset of collapse using three-dimensional general-relativistic hydrodynamics with…
We present the first three-dimensional, fully general-relativistic magnetohydrodynamic (3D GRMHD) simulation of a black hole (BH) formed from the collapsed core of a massive star. The ability to self-consistently capture the birth of a…
I present results from magnetohydrodynamic (MHD) simulations of a gaseous envelope collapsing onto a black hole. These results support the notion that the collapsar model is one of most promising scenarios to explain the huge release of…
The assembly of supermassive black holes poses a challenge primarily because of observed quasars at high redshift, but additionally because of the current lack of observations of intermediate mass black holes. One plausible scenario for…
Most gamma-ray bursts are made during the deaths of massive stars. Here the environmental circumstances, stellar evolutionary paths, and explosion physics that might produce the bursts are reviewed. Neither of the two leading models -…
We explore heavy element nucleosynthesis in the explosion of massive stars which are triggered by a quark-hadron phase transition during the early post bounce phase of core-collapse supernovae. The present study is based on general…
The gravitational collapse of a star can lead to the formation of a regular black hole. However, a key factor in this process is the transition of ordinary baryonic matter into a substance that forms the de Sitter core. However, the…
Collapsars -- massive stars whose cores promptly collapse into black holes (BHs) -- can power long-duration gamma-ray bursts (LGRBs) via relativistic, collimated, electromagnetically-driven outflows, or jets. Their power depends on the BH…
We explore the formation process of a black hole (BH) through the pair-instability collapse of a rotating Population III very massive star in axisymmetric numerical relativity. As the initial condition, we employ a progenitor star which is…
We present our numerical results of two-dimensional hydrodynamic (HD) simulations and magnetohydrodynamic (MHD) simulations of the collapse of rotating massive stars in light of the collapsar model of gamma-ray bursts (GRBs). Pushed by…
A novel concept has been recently proposed for explaining the temporal coincidence of some Gamma Ray Bursts (GRBs) with an associated Supernova (SN) in terms of the gravitational collapse of a neutron star (NS) to a Black Hole (BH), induced…
Long Gamma Ray Bursts (lGRBs) are associated with jets in Type Ic broadline supernovae. The Collapsar model provides a theoretical framework for the jet formation from the core collapse of a massive star in such supernovae. The GRB can only…
Core-collapse supernova explosions play a wide role in astrophysics by producing compact remnants (neutron stars, black holes) and the synthesis and injection of many heavy elements into their host Galaxy. Because they are produced in some…
The r-process nucleosynthesis in core-collapse supernovae (CC-SNe) is studied, with a focus on the explosion scenario induced by rotation and strong magnetic fields. Nucleosynthesis calculations are conducted based on magneto-hydrodynamical…
Long-term neutrino-radiation hydrodynamics simulations in full general relativity are performed for the collapse of rotating massive stars that are evolved from He-stars with their initial mass of $20$ and $32M_\odot$. It is shown that if…
Observations of distant bright quasars suggest that billion solar mass supermassive black holes (SMBHs) were already in place less than a billion years after the Big Bang. Models in which light black hole seeds form by the collapse of…
We perform the first magnetohydrodynamic simulation tracking the magnetosphere of a collapsing magnetar. The collapse is expected for massive rotating magnetars formed in merger events, and may occur many hours after the merger. Our…