Two shell collisions in the GRB afterglow phase
Abstract
Strong optical and X-Ray flares often appear in the afterglow phase of Gamma-Ray Bursts (GRBs). We perform high resolution numerical simulations of late collisions between two ultra-relativistic shells in order to explore these events. Such consecutive shells can be formed due to the variability in the central source of a GRB. We examine the case where a cold uniform shell collides with a self similar relativistic, shocked shell \citep{BM} in a constant density environment. We produce the corresponding light curves for the afterglow phase and examine the occurrence and chromaticity of optical and radio flares assuming different opening angles. We conclude that occurrence of optical and radio flares is possible for small opening angles of the jet. For our simulations we use the Adaptive Mesh Refinement version of the Versatile Advection Code \citep{Kep03,Mel08} while the synchrotron radiation has been calculated with the method introduced in \citet{HvE09b}.
- Publication:
-
Memorie della Societa Astronomica Italiana
- Pub Date:
- 2011
- DOI:
- 10.48550/arXiv.1103.2936
- arXiv:
- arXiv:1103.2936
- Bibcode:
- 2011MmSAI..82..137V
- Keywords:
-
- Gamma rays: hydrodynamics;
- Gamma rays: collisions;
- Radiation : Synchrotron;
- Radiation : light curves;
- Radiation: emission images;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Cosmology and Extragalactic Astrophysics
- E-Print:
- Accepted for publication in MNRAS