Predicting gamma-ray burster redshifts from their prompt emission properties

This paper presents a study of the relation between gamma-ray burster redshift and several of its prompt emission properties (spectral lag, light curve variability, peak energy, rise time and the peak bolometric flux Pbol). Simple predictors of log(1 + z) in terms of Pbol and the other indicators are derived. The typical scatter in the relations is 0.13 dex. An illustrative application to observations of GRB 090423 (z ∼ 8) is given.