Related papers: Opening Angles of Collapsar Jets
The role of relativistic jets in unbinding the stellar envelope during a supernova (SN) associated with a gamma-ray burst (GRB) is unclear. To study that, we explore observational signatures of stellar explosions that are driven by jets. We…
We present analytical modelling of conical relativistic jets, in order to evaluate the role of the jet opening angle on certain key parameters that are inferred from VLBI radio observations of blazar nuclear jets. The key parameters…
Motivated by the many associations of $\gamma$-ray bursts (GRBs) with energetic supernova (SN) explosions, we study the propagation of relativistic jets within the progenitor star in which a SN shock wave may be launched briefly before the…
Long-duration, spectrally-soft Gamma-Ray Bursts (GRBs) are associated with Type Ic Core Collapse (CC) Supernovae (SNe), and thus arise from the death of massive stars. In the collapsar model, the jet launched by the central engine must bore…
According the Collapsar model long gamma-ray bursts (LGRBs) involve relativistic jets that puncture the envelope of a collapsing star, and produced the \gamma-rays after they break out. This model provides a theoretical framework for the…
Gamma-Ray Bursts are the most luminous events in the Universe, and are excellent laboratories to study extreme physical phenomena in the cosmos. Despite a long trajectory of progress in understanding these highly energetic events, there are…
We examine millisecond magnetars as central engines of Gamma Ray Bursts' (GRB) prompt emission. Using the proto-magnetar wind model of Metzger et al. 2011, we estimate the temporal evolution of the magnetization and power injection at the…
Gamma-ray bursts (GRBs) are known to be highly collimated events, and are mostly detectable when they are seen on-axis or very nearly on-axis. However, GRBs can be seen from off-axis angles, and the recent detection of a short GRB…
We numerically investigate the jet propagation through a rotating collapsing Wolf-Rayet star with detailed central engine physics constructed based on the neutrino-driven collapsar model. The collapsing star determines the evolution of mass…
Gamma-ray bursts (GRBs) are luminous stellar explosions characterized by the ejection of relativistic jets. This work proposes a novel paradigm to study these GRB jets. By analyzing the timing information of prompt pulses and X-ray flares,…
It is generally supposed that a transition from the normal decay phase (decay slope $\sim -1$) to a steeper phase (decay slope $\sim -2$) could be suggested as a jet break. The jet opening angle $\theta_{\rm jet}$ is then calculated from…
After many years of speculation, recent observations have confirmed the association of gamma-ray bursts with core-collapse supernova explosions from massive stars. This association carries with it important consequences. The burst…
We perform a series of relativistic magnetohydrodynamics simulations to investigate how a hot magnetic jet propagates within the dynamical ejecta of a binary neutron star merger, with the focus on how the jet structure depends on the delay…
We present numerical solutions of the 2D relativistic hydrodynamics equations describing the deceleration and expansion of highly relativistic conical jets, of opening angles 0.05<theta<0.2, propagating into a medium of uniform density. Jet…
We use published data in radio, optical and X-ray bands to analyze and model afterglows of GW/GRB 170817A. Our analysis is based on a phenomenological gamma-ray burst generator model which we previously used to study the prompt gamma-ray…
With this paper we introduce the concept of apparent structure of a GRB jet, as opposed to its intrinsic structure. The latter is customarily defined specifying the functions epsilon(theta) (the energy emitted per jet unit solid angle) and…
The observations of jet breaks in the afterglows of short gamma-ray bursts (SGRBs) indicate that the jet has a small opening angle of < 10{\deg}. The collimation mechanism of the jet is a longstanding theoretical problem. We numerically…
I review aspects of the theory of long-duration gamma-ray burst (GRB) central engines. I focus on the requirements of any model; these include the angular momentum of the progenitor, the power, Lorentz factor, asymmetry, and duration of the…
Thanks to the rapid follow-up observations by \textit{Swift}/XRT, a good part of Gamma-Ray Bursts (GRBs) high latitude emission have been observed in X-ray band. Some of them even show a dropdown decay after this period, which strongly…
We study, analytically and numerically, the structure and evolution of relativistic jetted blast waves that propagate in uniform media, such as those that generate afterglows of gamma-ray bursts. Similar to previous studies, we find that…