Collisions between galaxies can make the universe poorer, blocking the birth of new stars: the galaxies themselves, in fact, following the impact, are unable to develop.
This is indicated by the observation of the cosmic collision between two primitive galaxies which took place about nine billion years ago, made by the Alma radio telescope (Atacama Large Millimeter / submillimeter Array) of the Southern European Observatory (Eso).
The results are published in the journal Nature Astronomy by the group coordinated by Annagrazia Puglisi, of the British University of Durham.
Among the authors also researchers from the National Institute of Astrophysics (INAF) and the Universities of Padua and Bologna.
Astronomers have observed the ID2299 galaxy expel almost half of the gas it needs for star formation, which thus stops for several hundred million years, effectively compromising the development of the galaxy.
Scholars believe that this event was triggered by the collision with another galaxy.
According to experts, the ID2299 galaxy is rapidly losing material to create new stars.
The ejection is happening at a very high rate, equivalent to the amount of gas from 10,000 stars like the Sun per year.
Furthermore, as the galaxy is also forming stars hundreds of times faster than our Milky Way, the remaining gas will soon be consumed, extinguishing ID2299 in a few tens of millions of years.
For Antonello Calabrò, of INAF in Rome and co-author of the study, “these destructive phenomena affect 3% of all collisions between galaxies.
In the universe, we expect a rate of about five hundred events in a volume of one million cubic light years every billion years.
This rate therefore - he concludes - makes these events a significant channel for extinguishing star formation ”.
