The Consistency Of Standard Cosmology And The Batse Number Vs Brightness Relation

The integrated number—peak flux relation measured by BATSE is compared with different standard cosmological distributions for GRBs to check for consistency, which if any cosmological model is particularly implied, and hence what brightness—redshift relation is implied. The standard Friedmann Robertson Walker models were used with the assumption that the bursts are standard candles and have no number or luminosity evolution. Given a specific cosmology we used a free parameter, essentially the co‐moving coordinate number density of bursts, for a given Ω and spectral shape, to generate a best fit between the cosmology and the measured relation. Preliminary results are shown for the first 155 BATSE bursts. The best fits show a maximum burst redshift of the order of unity; however, significantly higher redshifts are possible for other fits.