Astron. Astrophys. Suppl. Ser. 138, 401-402
The hardness evolution of gamma-ray burst pulses
A. Crider1 -
E.P. Liang1 -
R.D. Preece2 -
M.S. Briggs2 -
G.N. Pendleton2 -
W.S. Paciesas2 -
D.L. Band3 -
Send offprint request: A. Crider
1 - Department of Space Physics and Astronomy, 6100 S. Main, Rice University, Houston, TX 77005-1892, U.S.A.
2 - Department of Physics, University of Alabama in Huntsville, Huntsville, AL 35899, U.S.A.
3 - Center for Astrophysics and Space Sciences 0424, University of California at San Diego, La Jolla, CA 92093, U.S.A.
Received January 21; accepted April 21, 1999
We have analyzed the evolution of the spectral hardness parameter, (the maximum of the spectrum) as a function of fluence in gamma-ray bursts. We fit 41 pulses within 26 bursts with the trend reported by [#!lian96!#, Liang & Kargatis (1996)] which found that decays exponentially with respect to photon fluence . We also fit these pulses with a slight modification of this trend, where decays linearly with energy fluence. In both cases, we found the set of 41 pulses to be consistent with the trend.
Key words: gamma-ray: bursts, observations