Returning ten billion years ago to the past of the universe, Hubble bumped into two pairs of quasars, very close to each other, thinking of them as two needles in a haystack.
Sometimes two of these cosmic ogre species come together during the merger of galaxies, forming a double quasar. Since these galaxies were more frequent several billion years ago, researchers direct their telescopes as far as possible to try to catch them.
Two ancient pairs of quasars discovered
And so it happened that the team recently came across one of these needles... and then the other, and it was actually Hubble who noticed them, more than 10 billion light years from here, and these two pairs of quasars on the ground looked like two simple glowing points.
So far, astronomers have discovered about 100 of these double objects when the galaxies are merged, but none of them is as old as these two new discoveries.
This study, the results of which are published in the journal, will give researchers a better understanding of the collisions between galaxies and the merging of their black holes in the early universe.
These mergers, in turn, form the structure of the galaxies, and when two neighbouring galaxies begin to deform under the influence of gravity, their interaction sends matter to the relevant black holes and then ignites their quasars.
Over time, the radiation of these giant light bulbs causes a powerful wind that blows around the gas, and without substance, star formation stops, and galaxies turn into elliptical galaxies.
Although astronomers are convinced of these results, they believe it is possible that these images of Hubble are actually double images of the same quasars.
If so, they would be the work of gravitational lenses. Let us recall that these phenomena occur when the gravity of a massive galaxy in the foreground divides and reinforces the light of an object located in the background into two mirror images.
However, researchers believe that this scenario is unlikely, as Hubble did not find any visible galaxy near two pairs of quasars.