Tail emission from a ring-like jet: its application to shallow decays of early afterglows and to GRB 050709
arXiv:astro-ph/0601670 · doi:10.1088/1009-9271/6/5/06
Abstract
Similar to the pulsar, the magnetic axis and the spin axis of the gamma-ray burst source may not lie on the same line. This may cause a ring-like jet due to collimation of the precessing magnetic axis. We analyze the tail emission from such a jet, and find that it has a shallow decay phase with temporal index equal to -1/2 if the Lorentz factor of the ejecta is not very high. This phase is consistent with the shallow decay phase of some early X-ray afterglow detected by {\it{swift}}. The ring-like jet has a tail cusp with sharp rising and very sharp decay. This effect can provide an explanation for the re-brightening and sharp decay of the X-ray afterglow of GRB 050709.
6 pages, 2 figures. Accepted by ChJAA
References in corpus (8)
- Physical processes shaping GRB X-ray afterglow lightcurves: theoretical implications from the Swift XRT observations
- Evidence for a Canonical GRB Afterglow Light Curve in the Swift/XRT Data
- The afterglow of GRB050709 and the nature of the short-hard gamma-ray bursts
- Late internal shock model for bright X-ray flares in Gamma-ray Burst afterglows and GRB 011121
- Swift observations of the X-ray bright GRB 050315
- The Case for Anisotropic Afterglow Efficiency within Gamma-Ray Burst Jets
- Afterglow Light Curves from Impulsive Relativistic Jets with an Unconventional Structure
- Tail Emission of Prompt Gamma-Ray Burst Jets