50 million light-year long gas filament discovered, confirming model of the evolution of the Universe

New research published today in the journal Astronomy & Astrophysics describes the discovery of the longest gas filament yet seen. At 50 million light years long, this thread of hot gas stretches between two vast clusters of galaxies that are in the process of merging together. This discovery strikingly resembles predictions from computer simulations about how structure in the Universe should appear and confirms the understanding of the way the Universe has evolved.

This study used data from the eROSITA space telescope and CSIRO’s ASKAP radio telescope in Western Australia. The x-ray measurements from eROSITA are sensitive to the hot gas present in the galaxy clusters, while the ASKAP radio data pick out emission associated with galaxies and arising from extended energetic jets powered by supermassive black holes within those galaxies. Combining the data from both facilities allows a unique perspective on the complex interplay between gas and galaxies in this system of merging galaxy clusters.

For many years we have known about the relationship between gas in galaxy clusters and the way the galaxies themselves influence and are influenced by such hot gas. In particular, the radio jets from galaxies with supermassive black holes are known to be able to push the hot gas within a cluster aside as they shoot out into space. The novel discovery with these latest observations arises from the unique nature of the extended hot gas filament. These kinds of structure have been predicted in the best current models of the Universe, but this is the first time such a clear example has been discovered.

The ASKAP telescope was able to image the entire merging cluster system in a single exposure due to the extremely large field of view of its Phased Array Feed (PAF) technology. The highly sensitive radio image spanning the entirety of this complex galaxy system has enabled the identification of many extended radio structures, associated with supermassive black holes. The way this extended radio emission is distorted in the comparatively dense cluster gas as these galaxies fall into the clusters helps to identify which way they are moving and in turn trace the gravitational influence of the complex cluster pair. This information adds evidence for the way such structures evolve, in support of the underlying model of the Universe. Find out more https://www.atnf.csiro.au/content/askapgasfilament#

Added by Annabelle Young on 2020-12-18