1998/01/31 by A. Panaitescu, P. Mészáros, P. Meszaros +1 · 3 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Gamma-ray bursts and supernovae #astro-ph
paper · pdf · doi:10.1086/305995
published as Astrophys.J. 503 (1998) 314-320 · 14 pages, 3 figures, to appear in ApJ, vol. 503; revised version, errors in some equations corrected, Figure 1 altered (includes a new parameter: the electron injection fraction), the discussion of the inhomogeneous external medium case (section [4]) was extended, references up-dated
arxiv created 1998/05/02 · openalex publication_date 1998/08/10 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/31
We present an analytical approach to calculate the hydrodynamics of the interaction between a relativistic ejecta and a surrounding medium, whose evolution serves as a model for gamma-ray burst (GRB) afterglows. We investigate the effect of the relevant model parameters on the X-ray, optical, and radio fluxes and the effect of a refreshed shock energy input and anisotropy in the ejecta on the shape of the light curves. We compare our numerical results to observed afterglows and give a quantitative description of the conditions (geometry and physical parameters) in the ejecta that are compatible with the light curves of the GRB 970508 afterglow, for which a large number of accurate flux measurements are available. We find that the radio, optical, and X-ray light curves of this afterglow can be explained satisfactorily within the spherically symmetric fireball model, assuming a delayed energy injection, or by an axially symmetric jet surrounded by a less energetic outflow.