Hydrogen is the most abundant element in the universe. It plays a decisive role in the birth of stars and is, in fact, the fuel that most of them consume for most of their lives. Hydrogen emits a very distinctive signal that radio astronomers can use to locate galaxies and try to understand how they form.
In 2014, researchers at the University of Swinburne, in Australia, managed to detect hydrogen in a galaxy located 3 billion light years from Earth. To do this, they used the Arecibo radio telescope, in Puerto Rico. Nobody had managed to find the trace of this gas at a greater distance, until now.
A group of scientists from different institutions, coordinated by astrophysicist Ximena Fernández, from Rutgers University, in New Jersey, has announced in the Astrophysical Journal Letters the detection of hydrogen in a galaxy located more than 5,000 million light years away , all a record.
Fernández and his collaborators, who used the Karl G. Jansky Very Large Array radio astronomical observatory in New Mexico, have been able to determine that it would have contained billions of young and very massive stars, surrounded by hydrogen clouds. “The signals we are referring to would have started their journey even before our planet existed, ” says Fernández. “After 5,000 million years traveling through space we have been able to capture them and we have observed this galaxy for the first time,” he adds.
In this sense, radio astronomers become, so to speak, archaeologists of the cosmos: the more distant the object they study is, the further back in time they travel . “This is precisely the objective of our project, to know the variations that gas experiences in galaxies throughout their history,” says Fernández. “In this way, we hope to find out, for example, if in the past they contained more gas that gave rise to new stars than today,” he concludes.
Image: ICRAR / Peter Ryan
