相关论文: The Beaming Factor and Other Open Questions In GRB…

Gamma-ray burst (GRB) central engines and jet production mechanisms are still open questions. Assuming that the shallow decay segments of canonical X-ray afterglow lightcurves of {\em Swift} GRBs are attributed to the magnetic dipole (MD)…

Gamma-ray burst (GRB) data suggest that the jets from GRBs in the high redshift universe are more narrowly collimated than those at lower redshifts. This implies that we detect relatively fewer long GRB progenitor systems (i.e. massive…

If gamma-ray burst (GRB) emission is strongly collimated then GRBs occur throughout the Universe at a rate much higher than is detected. Since the emission from the optical afterglow is thought to be more isotropic than the gamma-ray…

Gamma-ray bursts with long durations are widely thought to arise from the collapse of massive stars, where the wind environment is unavoidable. It is also believed that $\gamma$-ray bursts come from jets. Considering these two points in…

We consider the time-dependent evolution of a relativistic jet following its breakout through the surface of a massive compact star, as envisaged in the collapsar model of gamma-ray bursts. At breakout, the jet is tightly collimated by the…

Tail emission of the prompt gamma-ray burst (GRB) is discussed using a multiple emitting sub-shell (inhomogeneous jet, sub-jets or mini-jets) model, where the whole GRB jet consists of many emitting sub-shells. One may expect that such a…

Gamma-Ray Bursts (GRBs) are now considered as relativistic jets. We analyze the gravitational waves from the acceleration stage of the GRB jets. We show that (i) the point mass approximation is not appropriate if the opening half-angle of…

We show that simple kinematic arguments can give limits on the timescale and amplitude of variabilities in gamma-ray burst (GRB) afterglows, especially when the variability timescale is shorter than the observed time since the burst \Delta…

The nearest GRB 170817A provided an opportunity to probe the angular structure of the jet of this short gamma-ray burst (SGRB), by using its off-axis observed afterglow emission. It is investigated that whether the afterglow-constrained jet…

Extensive observational campaigns of afterglow hunting have greatly enriched our understanding of the gamma-ray burst (GRB) phenomenon. Efforts have been made recently to explore some afterglow properties or signatures that will be tested…

We present multi-color optical and two-frequency radio observations of the bright SAX event, GRB 990510. The well-sampled optical decay, together with the radio observations are inconsistent with simple spherical afterglow models. The…

Taylor et al. (2004) reported recently on the first direct measurement of the apparent size of a GRB afterglow. Here we confront these observations with the predictions of the fireball model. We use a simple model to study numerically the…

We study the morphology of gamma-ray burst (GRB) afterglows viewed off-axis using a simplified analytical model. We consider steep jets, which are expected to be the most common type. These jets, characterized by steep lateral gradients in…

We present a general method for testing gamma-ray burst (GRB) jet structure and carry out a comprehensive analysis about the prevalent jet structure models. According to the jet angular energy distribution, we can not only derive the…

We investigate the dynamical evolution of double-sided jets and present detailed numerical studies on the emission from the receding jet of gamma-ray bursts. It is found that the receding jet emission is generally very weak and only…

The angular distribution of GRB jets is not yet clear. The observed luminosity of GRB 170817A is the lowest among all known short GRBs, which is best explained by the fact that our line of sight is outside of the jet opening angle,…

In this study, the light curves and spectrum of the photospheric thermal radiation from ultrarelativistic gamma-ray burst (GRB) jets are calculated using 2D relativistic hydrodynamic simulations of jets from a collapsar. As the jet…

Gamma-ray bursts observed in high-energies allow the investigation of the emission processes of these still puzzling events. In this study, we perform general relativistic magnetohydrodynamic (GRMHD) simulations to investigate GRB 090510, a…

Sharp breaks have been observed in the afterglow light curves of several GRBs; this is generally explained by the jet model. However, there are still some uncertainties concerning this interpretation due to the unclear hydrodynamics of jet…

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…