The clustering of gamma-ray bursts in the Hercules-Corona Borealis Great Wall: the largest structure in the Universe?

TL;DR

This paper investigates the existence of the Hercules-Corona Borealis Great Wall, a large gamma-ray burst clustering at redshift 2, using statistical analysis and discussing its implications as potentially the largest known structure in the Universe.

Contribution

The study confirms the clustering of gamma-ray bursts at redshift 2 and discusses its possible status as the largest structure, emphasizing the need for future homogeneous data from missions like THESEUS.

Findings

Confirmed clustering in reliable data set

Discussed cosmological and astrophysical origins

Highlighted importance of future gamma-ray burst data

Abstract

The Hercules-Corona Borealis Great Wall is a statistically significant clustering of gamma-ray bursts around redshift 2. Motivated by recent theoretical results indicating that a maximal Universal structure size may indeed coincide with its estimated size (2-3Gpc), we reexamine the question of this Great Wall's existence from both observational and theoretical perspectives. Our statistical analyses confirm the clustering's presence in the most reliable data set currently available, and we present a video showing what this data set looks like in~3D. Cosmological explanations (i.e. having to do with the distribution of gravitating matter) and astrophysical explanations (i.e. having to do with the rate of star formation over cosmic time and space) regarding the origin of such a structure are presented and briefly discussed and the role of observational bias is also discussed at length. This, together with the scientific importance of using gamma-ray bursts as unique cosmological probes, emphasises the need for future missions such as the THESEUS satellite which will provide us with unprecedentedly homogeneous data of gamma-ray bursts with measured redshifts. We conclude from all this that the Hercules-Corona Borealis Great Wall may indeed be the largest structure in the Universe - but to be able to decide conclusively whether it actually exists, we need THESEUS.