The W. M. Keck Observatory on the summit on Maunakea, Hawaii has helped an international team of scientists to detect and confirm the faintest galaxy from the early Universe.
In addition to relying on the world’s most powerful telescope for the discovery, the team also used gravitational lensing to be able to spot the incredibly faint object that was supposedly born right after the Big Bang.
The findings on the galaxy 13-billion-years-old will be featured in The Astrophysical Journal Letters. According to the scientists on the team, this particular galaxy has been there since the Universe was barely a toddler on a cosmic time scale.
The phenomenon that made the discovery possible was predicted by Einstein, and according to that, “an object is magnified by the gravity of another object that is between it and the viewer.”
In our case, the observed galaxy was behind the massive galaxy cluster MACS2129.4-0741, which created three different images of the object. It also helped that the team used Keck Observatory’s telescopes, which offered the best results paired with the gravitational force of the massive cluster of galaxies.
This kind of tools allows astronomers – and us, the mortal humans – to lay eyes on the beauty of the Universe like no other generation before us.
According to Marc Kassis, staff astronomer at Keck Observatory, the galaxy is so small and far away that its discovery could have been made only through lensing, which offered scientists the possibility of observing the edge of the visible Universe.
The identical images provided through lensing were initially seen separately at the Keck Observatory and in the Hubble Space Telescope data. All three images were then put together by the team, confirming they were the same and that they were looking at a triply-lensed system.
“This galaxy is exciting because the team infers a very low stellar mass or only one percent of one percent of the Milky Way galaxy,” explained Kassis.
Given its small size and the distance away from Earth, this galaxy could hold the answer to one of the questions that astronomers have been asking for a long time: What has caused the hydrogen gas at the very beginning of the Universe to become ionized about 13 billion years ago?
Image Source: Mashable