Correlations between intensity and spectral hardness in GRBs

Istituto di Astrofisica Spaziale, C.N.R., Roma, Italy

Received: 21 January 1999
Accepted: 7 June 1999

Abstract

We studied the distribution of the peak photon flux as a function of the spectral hardness (in this paper represented by the hardness-ratio) for the 4B BATSE catalog events. The maximum value of the peak distribution shows, for the first part of the hardness ratio variability range, clear positive correlation with the hardness-ratio up to a given value of the hardness-ratio. On the contrary, for higher hardness-ratio values, an anticorrelation is present. Possible interpretations of these peculiar behaviors are briefly discussed.