Investigating high redshift short GRBs: signatures of collapsars?

TL;DR

This paper examines whether some high-redshift short GRBs show signs of being collapsars, challenging the traditional classification based solely on duration and suggesting a more complex origin scenario.

Contribution

The study provides a comparative analysis of short and long GRBs across redshifts, highlighting potential collapsar signatures in short GRBs at high redshift.

Findings

Some high-redshift short GRBs exhibit features similar to long GRBs.

Host galaxy environments suggest possible collapsar origins for certain short GRBs.

The traditional short/long classification may need revision based on environmental and observational evidence.

Abstract

The conventional classification of Gamma-Ray Bursts (GRBs) as short or long bursts based on their duration is widely accepted as arising from different progenitor sources identified as compact object mergers and collapsars, respectively. However, recent observational shreds of evidence challenged this view, with signatures of collapsars in short GRBs and mergers in long GRBs. We conduct a comparative analysis of the characteristics of short and long GRBs, both at low and high redshifts, taking into account the locations and environments of their host galaxies. Our analysis suggests that some short GRBs at higher redshifts exhibit features similar to long GRBs, indicating a possible collapsar origin. Further investigation, utilizing multi-messenger observations, could provide a resolution to this issue.