Astron. Astrophys. Suppl. Ser. 138, 415-416
Istituto di Astrofisica Spaziale, C.N.R., Roma, Italy
Received January 21; accepted June 7, 1999
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.
of these peculiar behaviors are briefly discussed.
Key words: gamma-rays: bursts
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