sample of short bursts (denoted *‘short’*) and a comparable sample of long bursts (denoted *’long’*). However, the properties of the *’long’* sample cannot be compared directly with those of the *’short’* sample. The long bursts data is binned in longer time bins then the short bursts data. Therefore two equally intense bursts (one short and one long) would have a different signal-to-noise ratio (S/N). Hence, we generate a third sample denoted *’noisy long’* by adding noise to the *’long’* sample so that the S/N of the bursts in this sample would be comparable to the S/N of the *’short’* sample. Finally, in order to determine the shortest time scale in long bursts, we consider a sample of long bursts with a good TTE coverage of the first second. This sample is called *’high res long’*.

The *’short’* data sample\[shorts\]
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There are about 400 records of short bursts in the BATSE 4B-catalog. However most of these bursts are too faint and it is impossible to retrieve their temporal features. Furthermore, not all short bursts have a good TTE coverage. There is a trade-off between the sample size, the resolution and the signal to noise ratio. We consider, here, a sample 