Related papers: Proto-Magnetars as GRB Central Engines: Uncertaint…
Gamma-ray bursts (GRBs) are promising as sources of neutrinos and cosmic rays. In the internal shock scenario, blobs of plasma emitted from a central engine collide within a relativistic jet and form shocks, leading to particle acceleration…
We calculate the steady-state properties of neutrino-driven winds from strongly magnetized, rotating proto-neutron stars (`proto-magnetars') under the assumption that the outflow geometry is set by the force-free magnetic field of an…
Early shallow-decaying X-ray afterglows of gamma-ray bursts (GRBs) may be attributed to the dipole radiations of newly-born magnetars. Assuming that the GRB jets powered by magnetars are quasi-universal, we find that the jet structure can…
It is generally believed that long-duration gamma-ray bursts (GRBs) are associated with massive star core-collapse, whereas short-duration GRBs are associated with mergers of compact star binaries. However, growing observations have…
The origin of magnetic fields that permeate the blast waves of gamma-ray bursts (GRBs) is a long-standing problem. The present paper argues that in four GRBs revealing extended emission at >100 MeV, with follow-up in the radio, optical and…
A review is presented of the fireball model of gamma-ray bursts (GRBs), and of the production in GRB fireballs of high energy protons and neutrinos. Constraints imposed on the model by recent afterglow observations, which support the…
In less than a decade, fast radio bursts have gone from a single debated curiosity to a diverse extragalactic population with established host galaxies and energy scales. While a wide range of models remain viable, the central engines of…
A newly born millisecond magnetar is thought to be the central engine of some gamma-ray bursts (GRBs), especially those that present long-lasting X-ray plateau emissions. By solving the field equations, we find that when the rotational…
Ultra-high-energy, >10^19 eV, cosmic-ray and high energy, ~10^14 eV, neutrino production in GRBs is discussed in the light of recent GRB and cosmic-ray observations. Emphasis is put on model predictions that can be tested with operating and…
While there is mounting evidence that long Gamma-Ray Bursts (GRBs) are associated with the collapse of massive stars, the detailed structure of their pre-supernova stage is still debatable. Particularly uncertain is the degree of mixing…
The shallow decay phase and flares in the afterglows of gamma-ray bursts (GRBs) is widely believed to be associated with the later activation of central engine. Some models of energy injection involve with a continuous energy flow since the…
Gamma ray bursts (GRB's) often feature subpulses that have a distinctively asymmetric profile -- they rise quickly and decay much more slowly, while their spectrum softens slightly with observer time. It is suggested that these subpulses…
Observations and models of GRBs are reviewed with an emphasis on the early phase of the burst. Recent revision of the early afterglow model is described.
The discovery of a number of gamma-ray bursts with duration exceeding 1,000 seconds, in particular the exceptional case of GRB 111209A with a duration of about 25,000 seconds, has opened the question on whether these bursts form a new class…
Our understanding of the engines and progenitors of gamma-ray bursts has expanded through the ages as a broader set of diagnostics has allowed us to test our understanding of these objects. Here we review the history of the growth in our…
I describe electromagnetic model of gamma ray bursts and contrast its main properties and predictions with hydrodynamic fireball model and its magnetohydrodynamical extension. The electromagnetic model assumes that rotational energy of a…
Recent measurements by the Pierre Auger Observatory suggest that the composition of ultra-high energy cosmic rays (UHECRs) becomes dominated by heavy nuclei at high energies. However, until now there has been no astrophysical motivation for…
We present a set of numerical simulations of stellar explosions induced by relativistic jets emanating from a central engine sitting at the center of compact, dying stars. We explore a wide range of durations of the central engine activity,…
The origin of the X-ray afterglows of gamma-ray bursts has regularly been debated. We fit both the fireball-shock and millisecond-magnetar models of gamma-ray bursts to the X-ray data of GRB 130603B and 140903A. We use Bayesian model…
Millisecond magnetars, one of the potential candidates for the central engine of Gamma-ray bursts (GRBs), can experience significant magnetic field enhancement shortly after their formation. In some cases, this evolution is further…