Scientists from the National Astrophysical Institute of Italy in Bologna report the discovery of the largest and most severe object of the time of the early Universe - a huge supercluster of galaxies, located 11 billion light years away and appearing only 2.3 billion years after the Big Bang. The discovery of astronomers is reported in an article in the journal Astronomy & Astrophysics.
The Italian scientists made their discovery during the observation of about ten thousand ancient galaxies, comparable in size to the Milky Way and existing in the first two billion years after the Big Bang. In the course of their research, astronomers hoped to understand the conditions in which they could appear and how the evolution of these objects took place.
Observations have shown that a rather large part of these galaxies (about 1 thousand) turned out to be concentrated in a relatively compact area of the Sextant constellation. By calculating the distance between them, as well as analyzing the manner of their movement, the researchers realized that the observed objects are part of a giant cluster. Scientists called it "Hyperion" - in honor of one of the twelve titans from Greek mythology, who were born to Uranus and Gaia.
Subsequent observations of the object suggested that the total mass of the discovered supercluster should be at least 270 trillion solar masses, which makes it comparable in size to the largest giant clusters of galaxies located "in the neighborhood" with the Earth.
“We first discovered such a large cluster located at such a great distance from us. All known objects of this type, previously discovered, are located in a more “modern” part of the Universe, where they had enough time to gain mass and evolution. The discovery of “Hyperion” was a big surprise for us, ”explains the astronomer Olga Kuchchati from the Italian National Astrophysical Institute in Bologna.
According to modern concepts, the first galaxies appeared as a result of direct gravitational collision of giant gas clouds, which in turn, arose due to the uneven distribution of matter due to gravitational "echo" during the process of ultrafast expansion of space after the Big Bang.
Single galaxies were formed from some clouds, while others, larger ones, initiated the formation of tens and hundreds of galactic groups, which subsequently merged into clusters and superclusters.
The fact that the first galaxies that appeared in the first billion years after the Big Bang were supposed to differ from the later ones by small sizes and masses, the theoreticians said at the end of the last century. Recently, however, says Kuchchati, these assumptions have become questioned. The grain of these doubts was laid by observations with the help of modern ground-based and space telescopes, with the help of which scientists began to discover more and more ancient and large galaxies that appeared almost at the same time when the first stars were lit, and the Universe became completely transparent and accessible for observations.
According to the researchers, the Hyperion supercluster discovered from the more modern superclusters is distinguished by some features. For example, despite the similar mass and size, "Hyperion" is not at all similar in appearance to modern clusters. The latter have a more “branched” and heterogeneous structure, which is not at all observed in the “Hyperion”.
Explain what it is connected with, scientists can not yet, but plan to find out in the near future with the help of ground-based and orbital telescopes