Researchers build computer simulation that shows a way to detect the birth of the first stars

(Phys.org) -- In the model astrophysicists and astronomers use to describe the history of the universe, the Big Bang is used as the ultimate starting point, which is believed to have occurred some 13.7 billion years ago. After that, things grow a little murkier as at some point atoms were formed, then stars, and then entire galaxies. The timeline for these formations has been difficult to gauge though as there is so little evidence for researchers to look at; still most agree that the first stars likely appeared somewhere in the neighborhood of a hundred million years after the Big Bang. Now a team of researchers has found that in creating a simulation on a computer, as they describe in their paper published in the journal Nature, they might have found a way to detect the signature of the very first stars to have formed.

In creating the simulation the team looked at theories that suggest that during the early stages of the development of the universe, dark matter and regular (baryonic) matter began moving at different speeds due to light interacting with them. Dark matter is believed to be mostly impervious to the impact of light, whereas baryonic matter gets pushed when struck. But because this change in speed was occurring during the time when stars were forming (due to clouds of gas bunching together from their collective gravity and pressure from dark matter) the number of new stars being formed would be lessened, leading to a "lumpier" universe than has been previously thought.

The researchers used the relative differences in the speed of moving dark matter and baryonic matter and the way they believe radiation emitted from the earliest stars would have impacted those that came after, to calculate that the first stars would likely have appeared some 180 million years after the Big Bang. Using that information they were able to show via their simulation that the radiation emitted from the first stars should be detectable in the 50 to 100 megahertz range here today on Earth. Unfortunately, there are no radio telescopes currently operating in this range, so the team has suggested that one such as the Murchison Wide-field Array in Australia be modified to detect such signals. Doing so, they say would allow researchers to actually listen for clues left behind by the lumpiness of early star distribution and gas interactions allowing them for the first time to detect the presence of those first stars to be born.

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