Abstract We investigated how gamma-ray burst (GRB) prompt emission measurements are affected by increasing distance to the source. We selected a sample of 26 bright GRBs with measured redshifts z 3) GRBs to a sample of 72 observed high- z bursts and found that the two samples were not inconsistent with being drawn from the same underlying population. We conclude that (i) prompt emission durations (fluences) of high- z GRBs observed by Swift/BAT are most likely underestimations, sometimes by factors of about several tens (∼2), and (ii) changes in the average GRB prompt emission duration and fluence with increasing redshift are consistent with the tip-of-the-iceberg effect.
Moss et al. (2026) studied this question.