Old galaxies discovered in a young universe

Old galaxies discovered in a young universe
Old galaxies discovered in a young universe

An international team of scientists has found fifteen old galaxies in a very young universe.


Galaxies in the space surrounding us can be divided into young as a rule, spiral, actively forming stars, and old elliptical, where all the stars have already been born.

It is believed that when moving towards the beginning of the history of the Universe, galaxies of the second type should disappear: at the beginning of time there were only young and rapidly developing galaxies.

But galaxies found by an international team of scientists in a very young universe seem to have already passed a phase of active development. The formation of new stars in them is also not visible, although their age is about 12 billion years. If experts see them with already stopped star formation during the period when the Universe was eight times younger, then at what speed did the stars form in this galaxy before they stopped growing ?!

These distant and early massive galaxies The Holy Grail of Astronomy. Fifteen years ago, the theory was that they shouldn't exist at all; In 2004, I wrote a paper on the discovery of such galaxies just 3 billion years after the Big Bang. Now we have managed to trace them to the moment, only 1.6 billion years away from the Big Bang.

Karl Glazebrook, Study Author at Swinburne University, Australia

Astronomers have discovered only 15 galaxies, the light from which took about 12 billion years to reach us. Already in 1.6 billion years after the beginning of time, each of the "newcomers" has an average of about 100 billion stars. This can be compared to the Milky Way reaching similar results billions of years later.

The Milky Way is the galaxy that contains the Earth, the solar system and all the individual stars visible to the naked eye. Refers to barred spiral galaxies

This "acceleration" complements the results of early observations, according to which, the formation of stars in some galaxies of the past was incomparably faster, overtaking spiral galaxies many times. In general, it turns out that the processes of evolution of elliptical galaxies are so different from what happens with spiral galaxies that it takes the latter an incredibly long time to achieve the results of the former.


Most of the newly discovered galaxies are red, indicating that the phase of formation of new stars has already ended there.

© Caroline Straatman

That such early galaxies exist has puzzled astronomers. Galaxies, like humans, need some time to grow. Something extremely powerful (say, a superfast star formation phase) could cause galaxies to grow and mature at a tremendous rate. And to force these galaxies to "retire", events of no less magnitude were needed.

Lee Spitler, Study Author at the Australian Astronomical Observatory

In the near future, scientists intend to identify even earlier structures in order to see such processes, the content of which has not yet been studied.

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