The discovery calls into question the modern understanding of the early universe.
Using an array of radio telescopes ALMA, astronomers identified 39 extremely dim and massive galaxies, which escaped even from the sharp vision of the space telescope "Hubble". Scientists assume that these ancient relics are the ancestors of the elliptical galaxies observed today, but none of the modern theories of evolution of the universe can explain such many large starry megacities at the dawn of the universe. The results of the study are presented in the journal Nature.
"Previously, we have already managed to find in the young universe of the galaxy, extremely actively forming the stars, but their number is quite limited. Now we have identified a whole scattering of such objects in a small part of the sky, and, although the rate of formation of stars in them is slightly lower, they still do it 100 times faster than the Milky Way. It's important for us to study this point in the history of space to better understand the evolution of galaxies," says Tao Wang, a leading author of the study from Tokyo University, Japan.
The Hubble Space Telescope has provided us with an unprecedented view of an area of the universe that was previously invisible, but even it has been powerless in its search for some of the fundamental parts of the puzzle of the evolution of space. Astronomers have long suspected that somewhere in the depths of the universe, exotic objects are hiding from his eyes, and new generations of astronomical observatories have finally shown what was previously hidden.
"For the first time such a large population of massive galaxies was discovered at the turn of the first 2 billion years of life of the universe. Interestingly, the discovery contradicts modern models of that period of space evolution and will help to add unknown details to them," Tao Wang added.
But how can such vast galaxies be so elusive? The fact is that even though they are gigantic in size at the time, the light from the galaxies that came down to us is, firstly, very weak because of the high dust content in them and, secondly, because of the expansion of the universe and the huge distance to Earth, so stretched and shifted to the red side of the spectrum that it is invisible to Hubble. However, these limitations have not prevented ALMA antennas, which operate in the sub-millimeter wavelength range, from detecting radiation from extremely red objects and "seeing" through the dense veil that hides the light of stars.
What is remarkable about the discovery?
The more massive a galaxy is, the more massive a black hole in its heart is. Therefore, the study of these relics and their evolution will tell us more about the history of giant gravitational monsters. Also, large galaxies are closely related to invisible dark matter, which plays a role in their formation and distribution across the universe.
"Interestingly, the 39 open galaxies are very different from ours. If the solar system was inside one of them, and we would look at the sky on a clear night, we would see something completely different from the familiar picture of the Milky Way. On the one hand, the night sky would look much more majestic, as the high density of stars in these galaxies would be dotted with many bright lights. On the other hand, a large amount of dust would hide the stars from us, so those closer would lie on a huge black canvas," explained Kotaro Kono, co-author of the study from Tokyo University.
Astronomers note that these giant galaxies are invisible in the optical wavelengths for existing instruments, so today it is extremely difficult to investigate the star populations in them and their chemical composition, and to reveal all the secrets of the discovered giants will have to wait for the launch of future observatories, such as the space telescope NASA "James Webb".