New method allows astronomers to observe and study early stars and galaxies


Astronomers, led by the University of Cambridge, have developed a method they believe will allow them to observe and study early stars and galaxies and help explain how the Universe evolved from a vacuum after the Big Bang to the complex realm of celestial objects that we observe today, 13.8 billion years later.

The methodology developed by the Cambridge-led team will allow astronomers to observe the first stars through their interaction with hydrogen clouds, in the same way we would infer a landscape by looking at shadows in fog. Their findings are reported in the journal Nature Astronomy.

“At the time the first stars were formed, the Universe was essentially empty and composed mainly of hydrogen and helium. Due to gravity, the elements eventually came together and the conditions were created for fusion. nuclear, which formed the first stars. But they were surrounded by clouds of so-called neutral hydrogen, which absorb light very well, so it is difficult to detect or directly observe the light behind the clouds”, said Dr Eloy de Lera Acedo of Cambridge’s Cavendish Laboratory, the paper’s lead author.

The methodology developed by de Lera Acedo and his colleagues is part of the REACH experiment (Radio Experiment for the Analysis of Cosmic Hydrogen). It uses Bayesian statistics to detect a cosmic signal in the presence of telescope interference and general sky noise so that the signals can be separated.

The team used simulations to mimic a real-life observation using multiple antennas, which improves the reliability of the data – previous observations relied on a single antenna.

The construction of the telescope is currently being finalized in the Karoo radio reserve in South Africa, which is far from human-made radio frequency interference (eg TV and FM radio signals).

“We are extremely excited to see how well the system will perform and are fully confident that we will make this elusive detection,” said Professor de Villiers, co-leader of the project at the University of Stellenbosch in South Africa.

The first observations of REACH are expected later this year.


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