An international team of astronomers has discovered a group of 14 colliding galaxies that are more than 12 billion light-years distant from Earth. The protocluster, named SPT2349-56, appeared about a billion years after the Big Bang and, according to researchers, is now the largest object in the universe. The article of scientists was published in the journal Nature.
A protocluster is an emerging cluster (cluster) of galaxies. According to cosmological models, it should be composed of massive galaxies in which a burst of star formation occurs - a process by which new stars appear at a very high rate. However, until now, astronomers have not found dense enough clusters of galaxies approaching each other, which would be evidence of forming clusters.
Scientists have discovered SPT2349-56 with the SPT telescope in Antarctica and the ALMA radio telescope complex in Chile. It turned out that the star formation rate in the protocluster is 50-1000 times higher than in the Milky Way.
The galaxies are very close to each other, encompassing a region that is only 130 kiloparsecs (424 thousand light years) long. Moreover, the diameter of the Milky Way is 100 thousand light years. Comparison with other protoclusters showed that by now SPT2349-56 could have grown into the largest galactic structure in the universe.
Due to the fact that the speed of light, according to Einstein's theory of relativity, is the maximum allowable speed, the farther away a galaxy is from us, the younger we see it. Consequently, the apparent age of SPT2349-56 is about a billion years.