Scientists have discovered the most distant galaxy ever found- and it is nearly as old as the universe. The discovery of the 13.2 billion year old EGS8p7 galaxy has baffled the astrophysicists as current theories mean they should not have been able to see it. Usually, scientists measure the distance to old galaxies using redshift- an effect that means that light is stretched as it travels and becomes redder. The amount that happens is a measure of how far away it is.
But that technique cannot be used for the objects that came into existence with the very earliest universe, around 13.8 billion years ago. The early universe could not transmit light, because it could not move through the cosmos, and the radiation emitted by young galaxies would have been absorbed by clouds of atoms. That should mean that in theory there should not be any way of seeing the newly- discovered galaxy, EGS8p7. But, scientists can.
The team of researchers from Caltech and University College London are now trying to work out what made the discovery possible. “The suprising aspect about the present discovery is that we have detected this Lyman- alpha line in an apparently faint galaxy at redshift of 8.68, corresponding to a time when the universe should be full of absorbing hydrogen clouds”, said Richard Eliis, a professor of astrophysics at University College London, said in a statement. Scientists are now trying to work out how exactly they can see it.
The galaxy we have observed, EGS8p7, which is unusually luminous, may be powered by a population of unusually hot stars, and it may have special properties that enabled it to create a alarge bubble of ionized hydrogen much earlier than is possible for more typical galaxies at this times, “Sirio Belli, a Caltech graduate student who worked on the project, added. The findings, published in Astrophysical Journal Letters could give us a better understanding of how the universe, and we, were formed. Adi Zitrin, a hubble postdoctoral scholar in astronomy said, “We are currently calculating more throughly the exact chances of finding this galaxy and seeing this emission from it, and to understand whether we need to revise the timeline of the reionization, which is one of the major key questions to answer in our understanding of the evolution of the universe”.