Astronomers have been able to peer back into the early years of the universe since the arrival of the James Webb Space Telescope.
Now, this powerful space observatory has been able to observe the early stages of seven galaxies interacting to form a protocluster. A protocluster is defined, as where galaxies are gradually approaching each other to form an enormous cluster.
This
is said to be one of the farthest-located clusters of galaxies that astronomers
have observed and confirmed to date.
Teamwork
of Hubble and Webb
Initially, these seven galaxies were spotted using NASA's Hubble Space Telescope and appeared to be aligned in the same direction. Hubble, on the other hand, was unable to determine the distance between each galaxy.
The team then used the Webb telescope to confirm that these galaxies are indeed located at the same distance. Webb determined the distance between protocluster galaxies that existed during the initial years of the universe, just 650 million years after the Big Bang.
According to the press statement, these galaxies would have already merged by now, resulting in the formation of one of the largest and oldest known galaxy clusters in the universe. The cluster is likely to be more than 100 times more massive as compared to the Milky Way galaxy.
Scientists
highlight that these early stage development of galaxy clusters are rare to
spot. Additionally, these seven galaxies may have been among the first formed
galaxies in the universe's early years.
“This is a very special, unique site of accelerated galaxy evolution, and Webb gave us the unprecedented ability to measure the velocities of these seven galaxies and confidently confirm that they are bound together in a protocluster,” said Takahiro Morishita of IPAC-California Institute of Technology, the lead author of the study, in an official statement.
Measuring
the redshift
The Webb used the telescope's Near-Infrared Spectrograph (NIRSpec) instrument to calculate the precise distance. Using this instrument, astronomers were able to measure the redshift, which determines the distance of galaxies from the Earth. Simply put, the higher the redshift, the farther the galaxy is from the Earth. The wavelengths emitted by the galaxy are used to calculate the redshift.
The
findings revealed that each of these seven galaxies has the same redshift
(7.88). The galaxy cluster is located in the constellation Sculptor, nearly 13
billion light-years from Earth.
"We knew for a while from the Hubble data that there was an interesting over-density of galaxies. It came as a surprise when we first saw the spectra from JWST—all seven galaxies were aligned at the exact same redshift," said Takahiro Morishita, lead author of this study, in a statement.
Such discoveries will be accelerated by the upcoming Nancy Grace Roman Space Telescope. This, in turn, could shed light on the evolution of the universe, the formation of galaxies, and even some of the most perplexing mysteries surrounding black holes.
Reference: Astrophysical Journal Letters
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