SIMBAD references

The durations of 388 gamma-ray bursts detected by the Swift satellite, are analyzed statistically to search for subgroups. The results are then compared with results obtained earlier for data from the BATSE database. We apply the standard χ² test. As for data in the BATSE database, short and long subgroups are also reliably identified in the Swift data. An intermediate subgroup is also seen in the Swift database. The analysis of the entire sample of 388 GRBs provides a support for the existence of three subgroups.