A team of astrophysicists has successfully located and measured the farthest galaxy ever recorded. Its name is EGSY8p7 and it has been discovered thanks to the infrared spectrograph of the Keck observatory called MOSFIRE that uses a detection system of the Lyman-alpha emission line, a particular and old signature of hot hydrogen gas. These rare, huge, glowing gas clouds of the early Universe contain hydrogen and can reach about 300,000 light-years in diameter .
“We often see the Lyman-alpha hydrogen emission line in nearby objects, as it is one of the reliable markers of star formation. However, as we penetrate deeper into the Universe, and therefore back to earlier times, the space between galaxies contains an increasing number of dark hydrogen clouds that absorb this signal, “says Adi Zitrinm, leader of the study. .
What is surprising about this discovery is that they managed to detect this Lyman-alpha line in an apparently faint galaxy at a time when the universe was less than 600 million years old and when Lyman-alpha radiation was free to travel through the universe. unobstructed space, which again gives us clues about how the universe evolved in its first hundreds of millions of years.
According to the authors, “it may be that the galaxy we have observed, EGSY8p7, which is unusually luminous, has special properties that allowed it to create a large bubble of ionized hydrogen much earlier than was possible in the most typical galaxies of these times of cosmos”.
The study has been published in The Astrophysical Journal Letters .
