In an article published in Astrophysical Journal Letters, Caltech University researchers have reported the detection of possibly the farthest galaxy EGS8p7, which is more than 13.2 billion years old. According to the previous scientific reports, the universe is about 13.8 billion years old.
An ex-Caltech faculty Richard Ellis and NASA’s Hubble Postdoctoral Scholar in Astronomy Adi Zitrin are the authors of the study. Richard Ellis recently retired from Caltech after 15 years of service.
The galaxy EGS8p7 was discovered earlier this year, but more investigation had been initiated after the data generated by the Spitzer Space Telescope and NASA’s Hubble Space Telescope. To determine the galaxy’s redshift, astronomers gathered the spectrographic analysis data using Hawaii’s W.M. Keck Observatory‘s MOSFIRE – Multi-Object Spectrometer For Infrared Exploration. Redshift results explored using the method similar to that of Doppler effect, but here researchers use light instead of sound.
Sirio Belli, Caltech graduate student who worked on the project, said in a statement:
“The galaxy we have observed is named EGS8p7, is unusually luminous and may be powered by a population of unusually hot stars. 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.”
When the Big Bang phenomenon occurred, our universe was a soup of charged particles (electrons and protons) and light (photons). After 380,000 years of the Big Bang, neutral hydrogen atoms filled the universe due to the combination of free electrons and protons as the universe cooled down. The first galaxies turned on and reionized the neutral gas when the universe was just half-billion to a billion years old. Neutral gas remains ionized today in the universe.
“If you look at the galaxies in the early universe, there is a lot of neutral hydrogen that is not transparent to this emission,” noted Adi Zitrin, while Richard Ellis said, “The surprising aspect about the present discovery is that we have detected this Lyman-alpha line in an apparently faint galaxy, corresponding to a time when the universe should be full of absorbing hydrogen clouds.”[ Source ]