EFFECTS OF VARIABLE C-MIN ON GAMMA-RAY BURST C-MAX C-MIN DISTRIBUTIONS/

Claims continue to be made that detector selection effects can explain the deviation of the gamma-ray burst brightness distributions from th e -3/2 power law expected for homogeneous burst sources. However, thes e effects are insufficient to explain the BATSE observations. The BATS E sensitivity threshold does vary with time, independent of the burst brightness; however, a homogeneous distribution of standard candle sou rces would still produce a -3/2 power law. The variation in the thresh old does affect inhomogeneous source models. As an example, the effect of a time-varying C-min on the C-max/C-min distribution of an extende d Galactic halo model is shown here. To fit the BATSE C-max/C-min dist ribution including a varying C-min requires a larger observing distanc e (relative to the scale-height of the halo) than for a constant C-min ; however, the observations can still be fit using the halo models.