'Earliest galaxies in universe identified'

James Marshall
August 20, 2018

"A decade ago, the faintest galaxies in the vicinity of the Milky Way would have gone under the radar", said study co-author Sownak Bose with the Harvard-Smithsonian Center for Astrophysics.

The best scientists for many years studied the Universe, and a few ideas on decorating the flawless consistency of the Apocalypse.

They suggest that the galaxies called Segue-1, Bootes I, Tucana II and Ursa Major I belong to the group of galaxies that were the first to ever form in the universe, being thought to have formed over 13 billion years ago.

For millions of years after the Big Bang, there were no stars or galaxies. These sprawling cosmic neighbourhoods filled with stars and planets formed when many smaller building blocks collided and merged.

Scientists found evidence that the faintest satellite galaxies orbiting the earth's Milky Way galaxy are among the earliest galaxies in the universe.

"Finding some of the very first galaxies that formed in our universe orbiting in the Milky Way's own backyard is the astronomical equivalent of finding the remains of the first humans that inhabited the Earth", Professor Carlos Frenk, Durham University's Institute for Computational Cosmology Director, said.

Scientists claimed this discovery as hugely exciting. If the dark energy will become so strong it will tear everything apart all over 35-50 billion years. According to this theory our universe is about 13 billion years.

In the study published by Professor Frenk and his team in the Astrophysical Journal, they described how two of the satellite galaxy populations from their discovery could shed some light into the origins of the universe. The "function" gives the abundance of galaxies for a given luminosity. They are more or less located in the orbits around and near our galaxy.

According to the sources, the findings were corroborated by a galaxy formation model that the team had previously developed and which showed the new data fit perfectly with the astronomers' predictions. Clouds of red-hot Stardust is gradually cooled and formed a halo around the dark matter emerged after the Big Bang. As soon as the first galaxies were formed, the universe just burst into light and that ended the cosmic dark ages.

Phys.org continues, "The intense ultraviolet radiation emitted by the first galaxies destroyed the remaining hydrogen atoms by ionizing them (knocking out their electrons), making it hard for this gas to cool and form new stars".

As the hydrogen gathered into clouds, it began to cool.

The second generation of galaxies came much later, as the turbulent birth of stellar clusters absorbed free hydrogen and stopped this process on hundreds of millions of years. This next cosmological phase goes by the name "reionisation".

Eventually, the halos of dark matter became so large that even ionized gas was able to cool.

Galaxy formation resumed - culminating in the formation of spectacular bright galaxies like our own Milky Way.

Further study should help flesh out our understanding.

"If you go and examine these primitive galaxies, you should find freakish things about them. Being the first ones, they should have properties that are unique to them", said Prof Frenk.

The first population is extremely faint and includes the very first galaxies that were created. Other, heavier chemical elements were produced as a result of reactions inside stars. Nevertheless, the availability of different elements in the cosmos has changed since.

Although these ancient galaxies are found on our cosmic doorstep, that's because being relatively close makes these faint objects easier to find.

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