California Institute of Technology researchers recently announced that they have found what may be the farthest known galaxy in the universe – EGS8p7.
The galaxy, which is located 13.2 billion light-years away, is unusually bright for its age. So far, the newly found galaxy was also deemed as the oldest known galaxy although there may be others that are even older, scientists said.
CIT researchers started measurements on the galaxy earlier this year, but they weren’t the first to discover the galaxy. NASA’s Spitzer Space Telescope and ESA/NASA’s Hubble Space Telescope took the first images of EGSY8p7, but the Californian team’s measurements revealed that it is the farthest space object ever observed.
Yet, that may soon change, researchers noted, because increasingly advanced telescopes may soon detect even farther galaxies in short time. In May 2015, the EGS-zs8-1 galaxy was considered to be the farthest galaxy in the known universe.
Researchers were thrilled with the new discovery though EGSY8p7 displays some puzzling features. The newly ranked galaxy as the farthest out there was unusually bright for its age and location. Scientists believe that her brightness was amplified twice through the gravitational lensing effect. Without that effect, the galaxy would have remained hidden to current instruments.
The research team explained that they have measured the redshift of the galaxy in spectral imagery. So far, EGSY8p7 has the highest redshift intensity of all galaxies. And, the farther a space object is the reddish its color appears in spectroscopic observations.
But there is another peculiarity about the galaxy that had scientists scratching their heads. Since the galaxy was deemed the oldest in the known universe to date, the atomic hydrogen clouds that envelop these types of early galaxies should have blocked its light from reaching our planet. Because these clouds, which are a hallmark of early universe, would normally absorb light and keep early universe object in total darkness. Or at least that is what the standard cosmological model says. And, there must be plenty of these clouds across the 13.2 billion light-year-long distance the galaxy’s light had to travel to reach our optical instruments.
Some scientists blamed the anomaly on the “patchiness” of the reionization process, while others issued a new theory about “unusually hot stars” with special features that generated a dome of ionized hydrogen around them. The team is currently considering altering the timeline of the reionization in the standard model.
CIT scientists performed their own measurements on the galaxy with help from the MOSFIRE spectrometer near the Mauna Kea’s mountaintop in Hawaii.
Image Source: Wikipedia