Related papers: Binary Merger Progenitors for Gamma-Ray Bursts and…
Recent discoveries of gravitational wave (GW) events most likely originating from black hole (BH) + neutron star (NS) mergers reveal the existence of BH+NS binaries. The formation of BH+NS binaries and their merger rates through isolated…
The favoured progenitor model for short $\gamma$-ray bursts (SGRBs) is the merger of two neutron stars that triggers an explosion with a burst of collimated $\gamma$-rays. Following the initial prompt emission, some SGRBs exhibit a plateau…
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…
The production rate of compact objects, i.e. neutron stars (NS) and black holes (BH), in active galactic nuclei (AGN) and quasars (QSO), where the frequent supernova explosion is used to explain the high metallicity, is very high due to the…
In the collapsar scenario, gamma ray bursts are caused by relativistic jets expelled along the rotation axis of a collapsing stellar core. We discuss how the structure and time-dependence of such jets depends on the stellar envelope and…
We investigate a possible method for determining the progenitors of black hole (BH) mergers observed via their gravitational wave (GW) signal. We argue that measurements of the cross-correlation of the GW events with overlapping galaxy…
It is now generally accepted that long-duration gamma ray bursts (GRBs) are due to the collapse of massive rotating stars. The precise collapse process itself, however, is not yet fully understood. Strong winds, outbursts, and intense…
For the collapsar scenario to be effective in the production of Gamma Ray Bursts, the infalling star's angular momentum $J(r)$ must be larger than the critical angular momentum needed to form an accretion disk around a blackhole (BH),…
When massive stars exhaust their fuel they collapse and often produce the extraordinarily bright explosions known as core-collapse supernovae. On occasion, this stellar collapse also powers an even more brilliant relativistic explosion…
The progenitors of hydrogen-poor core-collapse supernovae (SNe) of types Ib, Ic and IIb are believed to have shed their outer hydrogen envelopes either by extremely strong stellar winds, characteristic of classical Wolf-Rayet stars, or by…
Dense, compact circumstellar media (CSM) are required to power strongly interacting supernovae, yet their physical origin remains uncertain. We present a systematic study of binary stellar evolution models computed with MESA, demonstrating…
We investigate a "hypernova" model for gamma-ray bursts (GRBs), i.e., massive C+O star model with relativistic jets. In this model, non-thermal precursors can be produced by the "first" relativistic shell ejected from the star. Main GRBs…
This meeting covered the range of cosmic explosions from solar flares to gamma-ray bursts. A common theme is the role of rotation and magnetic fields. A rigorous examination is underway to characterize systematic effects that might alter…
A fraction of the first generation of stars in the early Universe may be very massive ($\gtrsim 300~\mathrm{M_\odot}$) as they form in metal-free environments. Formation of black holes from these stars can be accompanied by supermassive…
The work presented here examines populations of double compact binary systems and tidally enhanced collapsars. We make use of BINPOP and BINKIN, two components of a recently developed population synthesis package. Results focus on…
Short gamma-ray bursts (sGRBs) show a large diversity in their properties. This suggests that the observed phenomenon can be caused by different "central engines" or that the engine produces a variety of outcomes depending on its…
For typical models of binary statistics, 50-70% of core-collapse supernova (ccSN) progenitors are members of a stellar binary at the time of the explosion. Independent of any consequences of mass transfer, this has observational…
We find significant fluctuations of angular momentum within the convective helium shell of a pre-collapse massive star - a core-collapse supernova progenitor - which may facilitate the formation of accretion disks and jets that can explode…
After initial claims and a long hiatus, it is now established that several binary stars emit high (0.1-100 GeV) and very high energy (>100 GeV) gamma rays. A new class has emerged called 'gamma-ray binaries', since most of their radiated…
Jets in long-duration $\gamma$-ray bursts (GRBs) have to drill through the collapsing star in order to break out of it and produce the $\gamma$-ray signal while the central engine is still active. If the breakout time is shorter for more…