Additional constraints on galactic coronal/extended halo source distributions from BATSE observations

Galactic corona/extended halo gamma‐ray burst source distributions are analyzed and compared to BATSE observations. Models have radial densities of the form n(r)=n_c[1+(r/r_c)^α]⁻¹, where α=2 for coronal dark matter, and the density is constant inside the core radius r_c. M31 is assumed to have a burst population similar to that of the Milky Way, while other Local Group galaxies are ignored. The parameter space of all such single‐population models is bounded, with 1.5≤α<4.0 and with minimum and maximum sampling distances caused by the off‐center location of the sun in the Milky Way, the presence of M31, and the shape of the log(N≳F_p) vs log(F_p) curve. Core radius limits are related to α and to the sampling distance. The constraints on these spatial distributions limit and to the sampling distance. The constraints on these spatial distributions limit the allowed burst luminosity functions, with the maximum range of luminosities (representing roughly a factor of 5) occurring for α=2. Two‐population models are examined comprising a local Galactic disk/halo population mixed with a coronal population. The local population introduces an isotropy which allows for smaller coronal core radii, but which also forces the corona to be sampled to larger distances. The largest range of coronal parameters occurs when no disk/halo sources are present. A maximum of 30% disk/halo bursts is allowed, but these force the corona to have the narrowest range of characteristics. Smaller statistical errors resulting from more BATSE bursts will cause the parameter space of the two‐population models to shrink faster than the single‐population corona/extended halo models.