Investigation of Redshift- and Duration-Dependent Clustering of Gamma-ray Bursts

TL;DR

This study investigates how gamma-ray bursts' spatial distribution varies with redshift and duration, finding marginal clustering in very short bursts but little redshift-dependent clustering overall.

Contribution

The paper introduces a novel analysis of GRB clustering based on redshift and duration using proximity measures and kernel density estimation.

Findings

Marginal clustering observed in GRBs shorter than 100 ms.

Little evidence for redshift-dependent clustering.

Analysis includes data from BATSE, Fermi/GBM, and Swift/BAT.

Abstract

Gamma-ray bursts (GRBs) are detectable out to very large distances and as such are potentially powerful cosmological probes. Historically, the angular distribution of GRBs provided important information about their origin and physical properties. As a general population, GRBs are distributed isotropically across the sky. However, there are published reports that once binned by duration or redshift, GRBs display significant clustering. We have studied the redshift- and duration-dependent clustering of GRBs using proximity measures and kernel density estimation. Utilizing bursts detected by BATSE, Fermi/GBM and Swift/BAT, we found marginal evidence for clustering in very short duration GRBs lasting less than 100 ms. Our analysis provides little evidence for significant redshift-dependent clustering of GRBs.