We have seen that a Galactic corona of high velocity neutron stars can easily account for the BATSE sky distribution and brightness distribution of gamma-ray bursts. Is there any evidence that high velocity neutron stars can produce burst-like behavior?
Yes, there is. Soft gamma-ray repeaters produce high energy transients whose durations overlap with those of gamma-ray bursts (see Figure 11), and whose characteristic spectral energies form a continuum with those of gamma-ray bursts (see Figure 12). The main distinction between soft gamma-ray repeaters and gamma-ray bursters is that the former have been clearly shown to repeat on time scales of days to years (Mazets et al. 1979, Laros et al. 1987, Atteia et al. 1987), whereas the latter have been thought not to repeat. But recently, a number of scientists have found strong evidence that gamma-ray bursters also repeat (Quashnock and Lamb 1993b, 1994; Wang and Lingenfelter 1993, 1995; Strohmayer, Fenimore, and Mirales 1994; Quashnock 1995). I will discuss the evidence for gamma-ray burst repeating in §IX.
Three soft gamma-ray repeaters are known. Two lie in the Galactic disk
at distances of 10's of kpc (SGRs 1806-20 and 1900+14); the third lies
in in the Large Magellanic Cloud in the halo of the Milky Way at a
distance of 50 kpc. All three are associated with young supernova
remnants (Evans et al. 1980, Kulkarni and Frail 1993, Kouveliotou et
al. 1994, Murakami et al. 1994, Hurley et al. 1994). In two cases, the
soft gamma-ray repeater lies far away from the center of the supernova
remnant, implying a neutron star velocity of 
km s
(Evans et al. 1980, Hurley et al. 1994). Clearly, high velocity
neutron stars can produce burst-like behavior.
If gamma-ray bursts come from high velocity neutron stars in a distant
Galactic corona, there are additional similarities between gamma-ray
bursts and soft gamma-ray repeaters. Both have luminosities 
erg s. Both also appear to have strong
magnetic fields, as we discuss below. These similarities and the ones
we discussed above suggest a physical or evolutionary relationship
between soft gamma-ray repeaters and gamma-ray bursts. The unification
of these two phenomena is a very attractive feature of the Galactic
hypothesis.