In this image, obtained with the help of a giant radio telescope, a blast wave is seen in the form of a bright arc, which is bent from the lower left corner to the upper right corner, swept over the cluster of “Sausage” galaxies.
The so-called “cosmic tsunami” is the awakening of a cluster of galaxies, affectionately called “Sousky”. Scientists believe that old galaxies can look younger again when a collision of galactic clusters occurs.
Astronomers made this discovery by studying CIZA J2242.8 + 5301, an ancient cluster of galaxies, located about 2.3 billion light years from Earth. The cluster, which they call “Sausage”, with many old red stars, awoke from the blast wave that caused the formation of new stars. The blast wave, which appeared at the collision of clusters, which scientists compare to the tsunami, was formed one billion years ago, and moves at a dizzying speed of 9 million km / h.
“We assumed that galaxies had nothing to do with this phenomenon, but it turned out that they, on the contrary, play a major role in this process,” said research co-director Andra Stroe, astronomer at the Leiden Observatory, in a statement. - “The fallen asleep galaxies in the“ Sausage ”cluster come back to life, stars begin to form with great speed in them. When we first saw the data, we could not believe that this could happen. ” For the first time, scientists have observed such a phenomenon, but theoretically almost every cluster of galaxies should have gone through a similar stage of frantic star formation. Unfortunately, scientists say, this resurrection of the stars will not be long.
“Star formation, which occurs at a tremendous speed, leads to the emergence of large mass stars with a short period of life, which will explode in supernovae after a few million years,” said David Sobral, another co-director of research from the Universities of Leiden and Lisbon. - “The outbreaks cause emissions from galaxies of a huge amount of gas and other components involved in star formation, therefore, very soon galaxies run out of fuel. After a rather long period of time, the collision of clusters makes the galaxies even more red and dead - they fall asleep again, and they have little chance of waking up again. ”
Stroe, Sobral and the international team of astronomers used several telescopes in the observatories of the Spanish La Palma and in Hawaii to study the cluster of sausage galaxies in the constellation Lizard in the northern hemisphere sky. The results of their observations were described in detail on April 24 in the Monthly Notices of the Royal Astronomical Society.
In the near future, the team plans to monitor a large number of galaxies in order to try to better trace the processes of collision of clusters.