Investigating the Possibility of Screening High-z GRBs based on BAT Prompt Emission Properties

TL;DR

This paper develops and refines criteria based on BAT prompt emission properties to efficiently identify high-redshift gamma-ray bursts, aiding early universe studies.

Contribution

It introduces updated screening criteria for high-z GRBs using spectral and temporal prompt emission data from Swift's BAT.

Findings

Effective high-z screening criteria established

Criteria improved with larger GRB sample

Enhanced ability to select high-z GRB candidates

Abstract

Being able to quickly select among gamma-ray bursts (GRBs) seen by the Swift satellite those which are high-z candidates would give ground-based observers a better chance to determine a redshift for such distant GRBs. Information about these high-z GRBs is important in helping to resolve questions about the early universe such as the formation rate of high-z GRBs, the re-ionization period of the universe, the metallicity of the early universe, and the Hubble expansion. Initially using a sample of 51 GRBs with previously measured redshifts, we have developed high-z screening criteria employing the GRB spectral as well as temporal characteristics of the prompt emission from the Burst Alert Telescope (BAT) on Swift. Now that the sample has increased to 81 GRBs, we have revisited the screening criteria and our methodology. Our updated high-z screening criteria are presented in this paper.