The recently discovered galaxy cluster spanning 3.3 billion light years is one of the largest structures in the universe, defying the comprehension of astronomers.
The structure, called the Giant Arc, is made up of many galaxies, clusters of galaxies, gas and dust. It is located 9.2 billion light years from Earth. Alexia Lopez, a doctoral student in cosmology at the University of Central Lancashire (UCL) in the UK, discovered the structure while mapping the object in the night sky based on the light of around 120,000 quasars, part shining galaxy nuclei, where supermassive black holes consume matter and spit out energy.
As it travels through matter between us and the quasar, light is absorbed by various elements, leaving a trail that provides a wealth of important information. Specifically, Lopez used traces of the element magnesium to determine the distances of gas and dust, as well as the location of the material in the night sky.
In this way, the quasars act as spotlights in a dark room, highlighting the material. In the middle of the cosmic map, the structure appears clear, like a great arch. Roger Clowes, Lopez’s instructor at UCL, suggests further analysis to make sure there are no mistakes. After performing two different tests of the data, the researchers determined that the probability that the structure of the giant arch was not real was less than 0.0003%. They reported on their findings on June 7 at the 238th meeting of the American Astronomical Society.
The Giant Arch is larger than other giant assemblages such as the Great Sloan Wall and the Antarctic Wall. The fact that such massive structures are concentrated in certain corners of the universe suggests that matter may not be evenly distributed.
