The BATSE gamma-ray burst spectral catalog. I. High time resolution spectroscopy of bright bursts using high energy resolution data

This is the first in a series of gamma-ray burst spectroscopy catalogs from the Burst and Transient Source Experiment (BATSE) on the Compton Gamma Ray Observatory, each covering a different aspect of burst phenomenology. In t his paper, we present time sequences of spectral fit parameters for 156 bur sts selected for either their high peak flux or fluence. All bursts have at least eight spectra in excess of 45 sigma above background and span burst durations from 1.66 to 278 s. Individual spectral accumulations are typical ly 128 ms long at the peak of the brightest events but can be as short as 1 6 ms, depending on the type of data selected. We have used mostly high ener gy resolution data from the Large Area Detectors, covering an energy range of typically 28-1800 keV. The spectral model chosen is from a small empiric ally determined set of functions, such as the well-known "GRB" function, th at best fits the time-averaged burst spectra. Thus, there are generally thr ee spectral shape parameters available for each of the 5500 total spectra: a low-energy power-law index, a characteristic break energy, and possibly a high-energy power-law index. We present the distributions of the observed sets of these parameters and comment on their implications. The complete se t of data that accompanies this paper is necessarily large and thus is arch ived in the electronic edition of the Astrophysical Journal.