ar X iv : a st ro - p h / 98 11 47 8 v 1 3 0 N ov 1 99 8 Afterglows from Gamma - ray Bursts
نویسنده
چکیده
The successful discovery of X-ray, optical and radio afterglows of gamma-ray bursts has significantly helped our understanding of these sources, and made possible the identification of host galaxies at cosmological distances. The energy release inferred in these outbursts rivals that of supernovae, while its photon energy output may considerably exceed it. Current models envisage this to be the outcome of a cataclysmic stellar event leading to a relativistically expanding fireball, in which particles are accelerated at shocks and produce nonthermal radiation. The substantial agreement between observations and the theoretical predictions of the fireball shock model provide confirmation of the basic aspects of this scenario. The continued observations show a diversity of behavior, providing valuable constraints for more detailed models. Crucial questions being now addressed are the beaming at different energies and its implications for the energetics, the time structure of the afterglow, its dependence on the central engine or progenitor system behavior, and the role of the environment on the evolution of the afterglow.
منابع مشابه
ar X iv : a st ro - p h / 97 11 35 4 v 1 2 8 N ov 1 99 7 Theoretical Models of Gamma - Ray Bursts 1
Models of gamma ray bursts are reviewed in the light of recent observations of afterglows which point towards a cosmological origin. The physics of fireball shock models is discussed, with attention to the type of light histories and spectra during the gamma-ray phase. The evolution of the remnants and their afterglows is considered, as well as their implications for our current understanding o...
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