The Dual Timescale Peak Flux and GRB Classes

Data mining techniques indicate that three gamma-ray burst classes exist. Our analysis indicates that the intermediate class is produced not from the fluence duration bias but from sample incompleteness caused by BATSE's preference to trigger on shorter bursts relative to longer bursts. We introduce the dual timescale peak flux to minimize this preference. We discuss this result in the context of other studies, and provide dual timescale peak fluxes for BATSE bursts with afterglows.