Anisotropy in the sky distribution of short gamma-ray bursts

We analyze the sky distribution of various types of cosmic gamma-ray bursts (GRBs): short, long, and intermediate; they are determined by burst duration T 90 (T 90 is the time during which 90% of the burst energy is accumulated). We have found an anisotropy in the distribution of intermediate (2 s < T 90 < 8 s) and short (T 90 < 8 s) GRBs in the form of spots with an enhanced GRB concentration near the Galactic coordinates l=115° and b=30°. Given the BATSE nonuniform exposure function, the statistical significance of the anisotropy is 99.89% for intermediate GRBs and 99.99% for short GRBs. Thus, we suggest that this anisotropy has a natural origin and is not caused by BATSE instrumental effects.