TITLE: GCN CIRCULAR NUMBER: 14746 SUBJECT: GRB 130603B: Swift-BAT Spectral lag analysis DATE: 13/06/04 02:39:24 GMT FROM: Scott Barthelmy at NASA/GSFC J. Norris (BSU), N. Gehrels (GSFC), S. D. Barthelmy (GSFC), T. Sakamoto (AGU) We report the spectral lag analysis for GRB 130603B (GCN Circ. 14735 & 14740) based on the BAT data. Using 2-ms binned light curves, the spectral lag for the 15-25 keV to 50-100 keV bands is 0.6 +-0.7 ms, and -2.5 +-0.7 mc for the 25-50 keV to 100-350 keV bands for both peaks combined. These lag values and the hard spectrum (GCN Circ. 14741) place this burst in the short burst category. There is no evidence for extended emission at the 0.005 cnts/det/sec level.