May give clues to the formation of the universe.
By Raif Karerat
Utilizing observations from the NASA/ESA Hubble Space Telescope, astronomers have discovered over 250 ultra-faint dwarf galaxies within three distant galaxy clusters.
Some of the galaxies formed just 600 million years after the Big Bang, meaning the newly discovered cosmic systems can offer astronomers a unique insight into the formation of the nascent universe.
Scientists said that the dwarf galaxies found at galaxy clusters Abell 2744, MACS0416 and MACS0717 are fainter than any other galaxy in the observable universe, according to Tech Times. They said that it took 12 billion years for the light from these galaxies to reach the Hubble Space Telescope, and this enabled scientists to trace back the galaxies at their earliest forms.
The team, headed by Dr. Hakim Atek of the Ecole Polytechnique Fédérale de Lausanne in Switzerland, studied images of Abell 2744, MACS0416 and MACS0717 taken as part of the Hubble Frontier Fields program — a 3-year, 840-orbit program that explores the most distant regions of space through gravitational lensing effects around six different galaxy clusters, according to Sci-News.
In a paper published in the Astrophysical Journal, Atek and his colleagues explained that the light emitted by the dwarf galaxies may have contributed to the epoch of reionization, a period in the early universe when thick hydrogen gas that covered everything began to dissipate that ended 700 million years after the Big Bang. Ultraviolet light was subsequently able to travel over great distances without being blocked by the hydrogen fog.