Rest frame properties of gamma-ray bursts

The small reference group of BATSE gamma-ray bursts with measured red-factors of optical afterglows is compared with the large comparison group of brightest BATSE bursts. These two groups are shown to be similar both in respect with distributions of measured $Ep$ parameters in the Observer frame and also in respect with frame-independent distributions of newly implemented cosmological invariant parameters (CIP). Using the known values of red-factors Z for the reference group, the distribution of $Ep(RF)$ is built for the rest frames of their sources. De-redshifted statistics of $Ep(RF)$ are compared with observed distributions of $Ep$ for the comparison group of bursts. From this comparison the collective estimation of red-shifts $Z=2.5–3.5$ has been performed for the group of brightest BATSE bursts.