BEACON TRANSCRIPT – Researchers were able to witness a unique view of how the universe looked like during the formation of the first stars and galaxies. This was possible by looking at a galaxy called A2744_YD4 which appeared to us as if the universe was in extreme infancy.
At the beginning, the universe was a big cloud of dust which then clumped into what we know today as stars and galaxies. The researchers were able to see how this process of clumping took place when they analyzed the galaxy A2744_YD4. For the analysis, they used two telescopes in northern Chile, the Atacama Large Millimeter Array (ALMA) and the Very Large Telescope (VLT).
The scientists revealed that this galaxy looks to us as it was during the period when the first stars and galaxies were formed, when the universe was only 600 million years old. Thus, A2744_YD4 is one of the earliest pieces of the universe.
The Big Bang did not spew fully formed stars and galaxies, but a hot cloud of neutrons, protons, and electrons. After 380,000 years, they cooled just enough to form nuclei. After these nuclei were able to attract atoms, they were no longer charged.
Thus, what occurred was some sort of a “switching off” of the universe. After 400 million years, the atoms were able to clump into stars, whose nuclear fusion allowed the universe to switch back on. One of the first places where this occurred was galaxy A2744_YD4.
It reached its current observable form after only 200 million years. Thus, the scientists are witnessing it shortly after its formation. Also, the light of this particular galaxy took 13.2 billion years to reach Earth, which is 96 percent of the total age of the universe.
Such dust clouds which are situated at such distances from Earth are quite hard to observe and analyze, but thanks to the completion of the 66 radio antennas of the ALMA telescope, scientists were able to witness them.
Firstly, the telescope picked up images of the galaxy in July 2016. Then, the scientists used the X-shooter instrument of the VLT and could reveal the young and messy galaxy. They noticed how stars were forming at a rate of 20 solar masses per year.
Next, the scientists will look at the composition of the dust clouds and the early stars, to understand how the stars came to produce other elements in the universe.
Image Source: Pixabay