The technique, which is presented in a new paper, looks for a type of signature of electromagnetic radiation known as a 21cm line, emitted by hydrogen atoms that fill the young ones. Universe In hundreds of thousands of years after the great explosion.
The signal is very weak, about a hundred thousand times weaker than the radio signals emitted by objects in our galaxy Milky Way. To separate the signal from all other noise detected by radio antennas, a complex data analysis will be required.
Eloy de Lera Acedo, an astronomer at the University of Cambridge in the UK and lead author of the new paper at statement (Opens in a new tab).
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By measuring the contrast between the radiation from hydrogen clouds and the signal behind them, astronomers hope to ‘see’ stars Like “shadows in the fog”.
“By the time the first stars formed, the universe was mostly empty and composed mostly of hydrogen and helium,” de Lira Acedo said in the statement. “Because of gravity, the elements eventually came together and conditions were right for nuclear fusion, which is what formed the first stars. But they were surrounded by clouds of neutral hydrogen, which absorb light well, so it is difficult to detect or observe the light directly behind the clouds.”
The James Webb Space Telescope, which recently released its first scientific images, is also looking for the first light in the universe, but using a different technology. Webb detects infrared radiation, which is essentially heat. Because heat can penetrate dust clouds, Webb also enables astronomers to peer into the most impenetrable regions of the universe.
The new radio astronomy method was developed as part of the Radio Experiment for Analysis of Cosmic Hydrogen (REACH) project and builds on previous observations that hinted at the discovery of a 21-centimeter line. However, those previous measurements could not be repeated, leading the scientists to believe the signal might be wrong.
“If we can confirm that the signal found in that previous experiment was indeed from the first stars, the effects would be enormous,” said de Lira Acedo.
The researchers used simulations that simulated real observations using multiple radio antennas, which improved data reliability compared to previous measurements based on a single antenna.
The new measurements will be made later this year in Karoo, South Africa.
“We are very excited to see how well the system will perform, and we have complete confidence that we will make this elusive discovery,” said Dirk de Villiers, a radio astronomer at Stellenbosch University in South Africa and co-lead author of the new paper in the statement.
Scientists have previously detected signals from the Big Bang in the form of cosmic microwave backgroundbut the appearance of the first stars in the universe after the dark ages of hundreds of thousands of years is still a missing piece.
the paper (Opens in a new tab) Published in Nature Astronomy on Thursday (July 21).