Threshold effects on gamma-ray burst distributions

Many of the important conclusions about Gamma-Ray Bursts follow from the distributions of quantities such as the peak flux. Because of the highly transient nature of the bursts, multiple selection thresholds can lead to various forms of data truncation, which can strongly affect the distributions obtained from the data if not accounted for properly. Therefore, a full multivariate analysis is required. Properly accounting for the effects of truncations and correlations, we extract the distributions of flux and fluence from the BATSE 3B Gamma-Ray Burst catalog. We find that the slope of the log N-log S relation at low values of S is increased, and that the fluence distribution has a sharper break in it than the peak flux distribution.