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 distribution, assuming burst origins in an extended halo with a radial source 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 luminosity function and space distribution to be studied, from which it is found that most of the observed bursts (the ''observed luminosity function'') are selected from a narrow luminosity range favoring one or both ends of the intrinsic luminosity function. Subsequent testing of Galactocentric halo models for consistency with the observational limits on anisotropies yields the strongest constraints on Galactic gamma-ray burst luminosity functions. These constraints require that the intrinsic luminosities span less than a factor of 5 for reasonable luminosity power-law indices. A radially dependent Galactic luminosity distribution or an evolution of sources can slightly relax these constraints.