Observing the birth of the first stars and galaxies was a goal for astronomers (Mariana Suarez/Getty)
A team of astronomers led by the University of Cambridge has developed an innovative method that allows them to “see” through the fog of the early universe, and detect light from stars And the first galaxies in a period that scientists consider “the dawn of the universe.” This methodology allows researchers to observe and study the first stars through the hydrogen clouds that filled the universe about 378,000 years after the Big Bang, according to to study published Thursday, July 21 in the journal Nature Astronomy.
In 2018, a radio telescope in the Australian outback detected a signal that looked like hydrogen gas absorbing ultraviolet radiation from the first stars, a few hundred million years after the Big Bang. But the signal was twice as strong as expected, which means the gas was much cooler than standard theory predicts.
Observing the birth of the first stars and galaxies has been a goal for astronomers for decades, as it will help explain how the universe evolved after the Big Bang into the complex world of celestial bodies we observe today after nearly 13.8 billion years. The signal that astronomers aim to detect is expected to be about a hundred thousand times weaker than other radio signals from the sky as well, for example, radio signals that originate in our galaxy.
While some astrophysicists have suggested that this signal may be caused by interactions with dark matter, others have called for more accurate measurements using better equipment and techniques. The signal must be about 100,000 times weaker than radio signals from the Milky Way. It is therefore difficult to rule out noise pollution from nearby radio sources or problems with the devices themselves.
The use of the same radio telescope causes distortions of the received signal, which can completely obscure the cosmic signal of interest. This is a severe challenge to the observing devices and techniques in modern radio cosmology. Such hardware distortions are usually blamed as the main bottleneck in this type of monitoring.
“At the time when the first stars formed, the universe was mostly empty and made up of hydrogen and helium,” said lead author of the study, Eloy de Lira Acedo, of the Cavendish Laboratory at the University of Cambridge. “Because of gravity, the elements eventually came together and the conditions were right for nuclear fusion, which is What the first stars looked like. But these stars were surrounded by clouds of neutral hydrogen, which absorb light well, so it is difficult to detect or notice the light directly behind the clouds.”
Asido added in a statement to Al-Araby Al-Jadeed that the methodology developed in the study aims to see primordial clouds and other sky noise signals, and to avoid the harmful effect of distortions caused by the radio telescope. This methodology will allow astronomers to observe the oldest stars through their interactions with clouds of hydrogen, in the same way that we infer a landscape by looking at shadows in fog. This method will also improve the quality and reliability of observations from radio telescopes looking at this important undiscovered time in the evolution of the universe. The first observations of this project are expected to be announced later this year.
The methodology developed by the team is used to detect a cosmic signal in the presence of telescope interference and general noise from the sky, where all these signals can be separated and distinguished. To do this, the latest technologies were needed jointly developed by multidisciplinary research teams.