
   I assume that can only be guessed at by the assumed energy of the
   event and the 1/r^2 law.  So, if the 1/r^2 law is incorrect (assume
   some unknown material [dark matter??] inhibits Gamma Ray propagation),
   could it be possible that we are actually seeing much less energetic
   events happening much closer to us?  The even distribution could
   be caused by the characteristic propagation distance of gamma rays 
   being shorter then 1/2 the thickness of the disk of the galaxy.