Time scales in long GRBs and the internal shock model
نویسندگان
چکیده
We show that according to the GRB internal shock model the pulse duration and the interval between neighboring pulses are correlated and have a similar distribution. We analyze a sample of bright long bursts and find that the pulses duration have a lognormal distribution while the intervals has an excess of long intervals (relative to lognormal distribution). This excess can be explained by the existence of quiescent times, long periods with no signal above the background. The lognormal distribution of the intervals (excluding the quiescent times) is similar and correlated with the distribution of the pulses width, in agreement with the predictions of the internal shock model. This suggests that quiescent times are produced by a different mechanism then the rest of the intervals, and possibly corresponds to periods in which the ‘central engine’ is not active at all.
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