Correlations between duration, hardness and intensity in GRBs

We present here the T90 and T50 distributions for different trigger time scales from the 3B catalog and confirm the bimodality established before with the 1B data. We show that the Hardness Ratio/duration anti-correlation is present in the 3B data set and we explore Hardness and Intensity correlations by studying various burst subsets. We discuss the impact of these correlations within the framework of a cosmological GRB origin hypothesis.