Anomalous grouping of some short BATSE GRBs

The power spectra of 457 short BATSE bursts were analyzed, focusing on the 64 ms lightcurves' tails in the low energy bands. Using MC simulations, 22 GRBs were identified with unusually high harmonic power above 0.03 Hz. The sky distribution of these bursts shows an extraordinarily strong dipole moment with a 99.994% significance.