UKZN astronomer leads team to map cosmic filament in 3D
Dr Mathilde Jauzac, of the University of KwaZulu-Natal and an international team of astronomers have unveiled the three dimensional structure of a cosmic filament in a new study.
This is the first time that the filament has been mapped in this manner.
Dr Jauzac, said, “Filaments of the cosmic web are extremely extended and diffuse, which makes them very difficult to detect, let alone study in three dimensions”.
A cosmic filament is part of a cosmic web that traces the distribution of matter in the universe. The team of astronomers discovered the filament while studying the galaxy cluster MACS J0717.5+3745, using the Hubble Telescope.
Galactic clusters are the biggest things in the universe to be held together by gravity, and they get bigger as more matter gets pulled to them along a cosmic filament.
In order to map out the filament Dr Jauzac applied a method called lensing. How that works is according to the theory of relativity, objects with a large mass bend light as it passes by them, which creates a sort of lens effect.
While the Hubble Telescope provided the best two dimensional map of the galaxies, it took adding its data to that observed from the Subaru and Canada-France-Hawaii telescopes to get the proper shape of the "lens" formed by galaxy cluster's gravity.
“The challenge,” explains co-author Jean-Paul Kneib from the Laboratoire d’Astrophysique de Marseille in France “was to find a model of the cluster’s shape which fitted all the lensing features that we observed.”
This research both helps confirm views of how small anomalies can grow into the massive structures we associate with the universe today. It also provides insights into the distribution of dark matter across the universe.