Chemical abundances and spatial distribution of Long Gamma-Ray Bursts

TL;DR

This study uses cosmological simulations to analyze the spatial distribution and chemical properties of Long Gamma-Ray Burst progenitors across redshifts, revealing their movement within host galaxies and metallicity evolution.

Contribution

It introduces a simulation-based analysis of Long Gamma-Ray Burst progenitors' locations and chemical properties as a function of redshift, supporting low metallicity scenarios.

Findings

GRB sites shift from galaxy centers at high redshift to outer regions at low redshift

Low metallicity cutoff models best fit current observations

GRB progenitors are generally metal-poor with evolving alpha-enhancement

Abstract

We analyse the spatial distribution within host galaxies and chemical properties of the progenitors of Long Gamma Ray Bursts as a function of redshift. By using hydrodynamical cosmological simulations which include star formation, Supernova feedback and chemical enrichment and based on the hypothesis of the collapsar model with low metallicity, we investigate the progenitors in the range 0 < z < 3. Our results suggest that the sites of these phenomena tend to be located in the central regions of the hosts at high redshifts but move outwards for lower ones. We find that scenarios with low metallicity cut-offs best fit current observations. For these scenarios Long Gamma Ray Bursts tend to be [Fe/H] poor and show a strong alpha-enhancement evolution towards lower values as redshift decreases. The variation of typical burst sites with redshift would imply that they might be tracing different part of galaxies at different redshifts.