EGSY8p7 Detection - The oldest galaxy ever found

The team at the California Institute of Technology (Caltech) has discovered a galaxy about 13.2 billion light-years from Earth and may be the farthest, oldest galaxy we've ever discovered.

Discover the oldest galaxy ever

According to scientists' estimates, the age of the universe is about 13.8 billion years and based on this, the EGSY8p7 galaxy has been found only "younger" than the universe about 600 million years. In theory, the EGSY8p7 will take over the oldest and most distant galaxy named EGS-zs8-1, co-discovered by Yale and California in the first month of May this year.

Sirio Belli, a graduate student at Caltech, a member of the research team, said they discovered the EGSY8p7 galaxy because of its extraordinary glow and thought it was supported by a group of unusually hot stars. "This galaxy has special properties that allow it to create a giant hydrogen ionized bubble sooner than many other popular galaxies at the moment," he said.

The EGSY8p7 galaxy is observed through the Hubble and Spitzer space telescopes.

Right after the Big Bang occurred, the universe was like a mess of charged particles and photons. When the universe reached half a billion to 1 billion years old, the first galaxies began to form and re-ionize inert gases. Until now, the universe is still ionized.

However, before re-ionizing, clouds containing inert hydrogen atoms can absorb a certain amount of radiation emitted by young, newly formed galaxies, including the spectral line of Lyman-alpha - a The spectral signature of hot hydrogen gas is heated by ultraviolet radiation from young stars and this spectral line is often associated with star formation.

Because of this radiation absorption, in theory, we cannot observe the Lyman-alpha spectral lines emitted by the EGSY8p7 galaxy. Adi Zitrin, a postdoctoral fellow in astronomy at NASA Hubble, said: "If you look at the galaxies that appeared in the early universe, you will see a lot of inert transparent hydrogen causing the this radiation cannot penetrate ".

This hindrance made discoveries more valuable, said researcher Richard Ellis at the Caltech institute, saying: "The amazing thing about this new discovery is that we were able to detect Lyman-alpha spectral lines in a faint galaxy, corresponding to the timeline when the universe is full of inert hydrogen-absorbing clouds ".

The team at Caltech is now continuing to calculate the possibilities and review the timeline of the re-ionization process. Zitrin said: " Re-ionization is one of the important questions to answer in order to reinforce our understanding of the development of the universe."