An international team of astronomers has found one of the largest superclusters of galaxies in the universe near the Milky Way. The supercluster has now been named the Vela supercluster. It has previously gone undetected, as it was hidden by the Milky Way’s stars and dust. It is also understood that its huge mass is influenced by the motion of the Milky Way.
Professor Matthew Colless from the Australian National University (ANU), who was part of the team that made the discovery, said in a statement:
“This is one of the biggest concentrations of galaxies in the Universe — possibly the biggest in the neighbourhood of our Galaxy, but that will need to be confirmed by further study.
“The gravity of the Vela supercluster may explain the difference between the measured motion of the Milky Way through space and the motion predicted from the distribution of previously mapped galaxies.”
— ANU Media (@ANUmedia) December 21, 2016
To confirm that the Vela supercluster was really a supercluster, Professor Colless used the Anglo-Australian Telescope to measure distances to many galaxies; by doing this, he was able to confirm earlier predictions that Vela was indeed a supercluster. He was also able to estimate the supercluster’s effect on the motion of the Milky Way.
The research involved astronomers from South Africa, Australia, and Europe. Two new Australian surveys that will start in 2017 will confirm the size of the Vela supercluster. Colless explained that:
“The Taipan optical survey will measure galaxy distances over a bigger area around Vela, while the WALLABY radio survey will be able to peer through the densest parts of the Milky Way into the supercluster’s heart.”
The research has been published in Monthly Notices of the Royal Astronomical Society.