Long-acting Engine or Strong Temporal Anisotropy Inferred from Variabilities of Gamma-Ray Burst Afterglows
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چکیده
We show that some types of variabilities of gamma-ray burst (GRB) afterglows are forbidden by simple kinematical arguments. These limits help us to identify the source of afterglow variabilities. Actually the afterglows of GRB 011211 and GRB 021004 violate these limits, implying that the compact object that powers GRB jets may continue to eject an intermittent outflow for a very long timescale (& 1 day) or that the GRB jet from the central engine may have a temporal anisotropy with a large brightness ratio & 10 and small angular structure . 10. Subject headings: gamma rays: bursts — gamma rays: theory — relativity
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تاریخ انتشار 2004