GALACTIC GAMMA-RAY BURST MODELS - CONSTRAINTS ON THE INTRINSIC LUMINOSITY FUNCTION

Constraints are found on the intrinsic luminosity function of Galactic gamma-ray bursts from analysis of the BATSE/PVO combined intensity di stribution, assuming burst origins in an extended halo with a radial s ource density decreasing beyond an homogeneous core, and assuming that the intrinsic luminosity function can be modeled as a truncated power law. Initially a spherical heliocentric extended halo is assumed as a first-order approximation. Analysis of the model log (N > F-p) versus log F-p curves allows the interaction between the intrinsic luminosit y function and space distribution to be studied, from which it is foun d that most of the observed bursts (the ''observed luminosity function '') are selected from a narrow luminosity range favoring one or both e nds of the intrinsic luminosity function. Subsequent testing of Galact ocentric halo models for consistency with the observational limits on anisotropies yields the strongest constraints on Galactic gamma-ray bu rst luminosity functions. These constraints require that the intrinsic luminosities span less than a factor of 5 for reasonable luminosity p ower-law indices. A radially dependent Galactic luminosity distributio n or an evolution of sources can slightly relax these constraints.