Gamma-Ray Burst Distribution

• Gamma-ray bursts are found to be distributed isotropically across the sky:

  

  ( Image of 1000 bursts location . The original image is from the BATSE Pages at GSFC.)

  ( Current BATSE map of Gamma-Ray Burst locations . Over 1221 sold.)

• The absence of a concentration toward the galactic plane implies that the GRBs are not associated with sources in the disk of our galaxy.

• Even galactic halo sources would show an asymmetric distribution (since we are not located at the centre of the Galaxy), and no such asymmetry is seen.

• We are thus forced to conclude that the GRBs originate outside the Milky Way.