A radio signal from the beginning of the universe could reveal how everything began
The signal – known as the 21-centimetre signal – could finally let us understand how the first stars and galaxies switched on, and brought the universe from darkness to light.
'This is a unique opportunity to learn how the universe's first light emerged from the darkness,' said co-author Anastasia Fialkov from Cambridge University, in a statement. 'The transition from a cold, dark universe to one filled with stars is a story we're only beginning to understand.'
The signal comes to us from more than 13 billion years ago, just a hundred million years after the Big Bang. The faint glow is created by hydrogen atoms that fill up the space between regions of space where stars are being formed.
Scientists now believe they will be able to use the nature of that signal to better understand the early universe. They will do that with a radio antenna called REACH – the Radio Experiment for the Analysis of Cosmic Hydrogen – which will try and capture radio signals to reveal data about the beginnings of the universe.
To better understand how that project might work, researchers created a model that predicted how REACH as well as another project called the Square Kilometre Array will be able to provide information about the masses and other details of the first stars.
'We are the first group to consistently model the dependence of the 21-centimetre signal of the masses of the first stars, including the impact of ultraviolet starlight and X-ray emissions from X-ray binaries produced when the first stars die,' said Professor Fialkov.
'These insights are derived from simulations that integrate the primordial conditions of the universe, such as the hydrogen-helium composition produced by the Big Bang.'
'The predictions we are reporting have huge implications for our understanding of the nature of the very first stars in the Universe,' said co-author Eloy de Lera Acedo, Principal Investigator of the REACH telescope.
'We show evidence that our radio telescopes can tell us details about the mass of those first stars and how these early lights may have been very different from today's stars.
'Radio telescopes like REACH are promising to unlock the mysteries of the infant Universe, and these predictions are essential to guide the radio observations we are doing from the Karoo, in South Africa.'
The work is described in a new paper, 'Determination of the mass distribution of the first stars from the 21-cm signal', published in the journal Nature Astronomy.
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