During those 13.8 billion years since the Big Bang, the Universe had enough time to spread all the light so that what we know as the ‘Observable Universe’ shall emerge. But how about detecting the light from the very first stars that were born? That is exactly what a team of scientists have in mind, although it sounds very unfeasible to some people.
Scientists working with the Murchison Widefield Array (MWA) radio telescope are tracking the signal from the first stars of the Universe. They formed after the Universe’s Dark Ages, when not even atoms existed.
Neutral hydrogen could be the key
In order to find the first light emitted by the oldest stars, scientists are first seeking the signal from neutral hydrogen, which is the gas that existed predominantly in the Universe after the Dark Ages.
To track the neutral hydrogen signal, the number of tiles of the MWA radio telescope was raised to 256, and also the scientists rearranged the entire array. All the data gathered is sent into a supercomputer called the Correlator.
First step has been made
The first analysis of the data gathered by the array has been published in a paper for Astrophysical Journal, and it can mean a huge step towards the ultimate goal of finding the first light from the oldest stars in the Universe. The research had the purpose of understanding how strong would the signal from the neutral hydrogen be. Thus, the lowest limit for the signal has been set.
Jonathan Pober, an assistant professor of physics at Brown University, stated:
We can say with confidence that if the neutral hydrogen signal was any stronger than the limit we set in the paper, then the telescope would have detected it,
These findings can help us to further constrain the timing of when the cosmic dark ages ended and the first stars emerged.
It’s true that the whole Universe might actually be a lot bigger than what we call ‘Observable Universe’, and without even considering those many theories about the Multiverse (the hypothetical existence of many other Universes). But the scientists’ seek for the light from the first stars is worth the effort anyway.