A team of Caltech researchers that has spent years searching for the earliest objects in the universe now reports the detection of what may be the most distant galaxy ever found. In an article published August 28, 2015 in Astrophysical Journal Letters, Adi Zitrin, a NASA Hubble postdoctoral scholar in astronomy, and Richard Ellis—who recently retired after 15 years on the Caltech faculty and is now a professor of astrophysics at University College, London—describe evidence for a galaxy called EGS8p7 that is more than 13.2 billion years old. The universe itself is about 13.8 billion years old.
[...] "The surprising aspect about the present discovery is that we have detected this Lyman-alpha line in an apparently faint galaxy at a redshift of 8.68, corresponding to a time when the universe should be full of absorbing hydrogen clouds," Ellis says. Prior to their discovery, the farthest detected galaxy had a redshift of 7.73.
One possible reason the object may be visible despite the hydrogen-absorbing clouds, the researchers say, is that hydrogen reionization did not occur in a uniform manner. "Evidence from several observations indicate that the reionization process probably is patchy," Zitrin says. "Some objects are so bright that they form a bubble of ionized hydrogen. But the process is not coherent in all directions."
"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 large bubble of ionized hydrogen much earlier than is possible for more typical galaxies at these times," says Sirio Belli, a Caltech graduate student who worked on the project.
"We are currently calculating more thoroughly 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," Zitrin says.
(Score: 2) by wonkey_monkey on Monday September 07 2015, @07:37AM
Yes, really. Problem?
systemd is Roko's Basilisk
(Score: 2) by Kell on Monday September 07 2015, @07:48AM
The informative wiki page says 3.798±0.037 billion years: https://en.wikipedia.org/wiki/Age_of_the_universe [wikipedia.org]
Scientists ask questions. Engineers solve problems.
(Score: 0) by Anonymous Coward on Monday September 07 2015, @09:12AM
It should note that is an estimate based on current knowledge, or something to that effect.
(Score: 2) by wonkey_monkey on Monday September 07 2015, @12:03PM
Given the amount of disagreement in mainstream physics surrounding the age of the universe (not much) I think the word "about" covers it.
systemd is Roko's Basilisk
(Score: 0) by Anonymous Coward on Monday September 07 2015, @04:56PM
Reminds me of the super precise radius of the proton.