A team of astronomers from the University of Virginia in Charlottesville (USA) has discovered, thanks to the Atacama Large Millimeter / submillimeter Array (ALMA), what appears to be the first known globular cluster about to germinate . It is an extremely massive cloud of molecular gas (it has 50 million times the mass of the Sun) but without the presence of stars. The study has been published in the Astrophysical Journal .
Globular clusters are one of the most primitive objects in the universe (they can contain up to a million ancient stars ) and finding them at this very early stage of their development is extremely difficult to find; so much so, that until now none had been detected .
“We can be in the presence of one of the oldest and most extreme modes of star formation in the Universe. This interesting object seems to be plucked directly from the early Universe; discovering an object that has all the characteristics of a globular cluster, but has not yet begun to form stars, is like finding a dinosaur egg about to hatch, “explains Kelsey Johnson, leader of the study.
The protostar supercluster in question is approximately 50 million light-years away , inside two colliding galaxies known as the Antenna galaxies. The striking thing about this supercluster is that it is in its original phase, giving scientists the opportunity to study the necessary conditions for an area that will later end up full of stars.
And it is that most globular clusters were formed about 12,000 million years ago, at the earliest stage in the history of the universe: “the probability of survival for a young and massive star cluster to remain intact is very low, of about one percent. External and internal forces tend to separate these objects, either forming open clusters like the Pleiades or completely disintegrating them to form part of the galactic halo, ”says Johnson.
Thanks to the ALMA telescope, astronomers have determined that this future star cluster is under extreme pressure: about 10,000 times more than known interstellar pressures , a circumstance that supports the theories that specified that the formation of globular clusters requires high pressures.
