Thanks to an international team of astronomers from the University of Geneva (UNIGE) and the James Webb Telescope (JWST), a galaxy where star formation stopped just 700 million years after the Big Bang has been discovered. This discovery casts doubt on current theories of galaxy evolution, because the “dying” of such systems occurs much faster than predicted by models. The results of the study are published in The Astrophysical Journal.
Revolutionary discovery
The galaxy RUBIES-UDS-QG-z7, discovered by the RUBIES program, has become the most distant galaxy among known “red and dead” galaxies. Its spectrum indicates the presence of an old stellar population at a time when the Universe was still very young. Scientists estimated that it accumulated stars of more than 10 billion solar masses for the first 600 million years of its existence, after which it suddenly stopped star formation.
It is hypothesized that RUBIES-UDS-QG-z7 may be the “germ” of modern giant elliptical galaxies. Its size is only 650 light-years across and its high density is reminiscent of the cores of ancient systems.
Contradictions with the theory
For a long time, it was thought that only galaxies actively producing stars existed in the early Universe. However, JWST, capable of “seeing” in the infrared, demonstrated the opposite: massive “quiet” galaxies were 100 times more common than models predicted. This means that there are many more dead galaxies in the young Universe than previously thought.
The team plans to investigate other “dead” galaxies from the early Universe to see if RUBIES-UDS-QG-z7 was a unique phenomenon or part of a broader trend.
This work not only reveals the mysteries of the past, but also raises new questions, one of which is: what exactly “kills” galaxies so early? The answers will change our understanding of the life cycle of galaxies, from birth to the last starburst.
We previously reported on how James Webb discovered a galaxy that dispelled the fog of the early Universe.
According to phys.org
