NOTTINGHAM, England, April 16 (UPI) -- British astronomers say they've determined fully evolved galaxies existed 4 billion years after the birth of the universe.
The University of Nottingham-led researchers said their finding challenges existing theories of the formation and evolution of galaxies.
The astronomers said they used the most detailed infrared images of a portion of the sky ever made. The images were taken by a United Kingdom Infra-Red Telescope near the summit of Mauna Kea, Hawaii, more than 13,000 feet above sea level.
Researchers used the images to estimate the mass of dark matter surrounding the old galaxies by measuring how closely the galaxies cluster. They said their calculations indicate the mass of dark matter surrounding those galaxies is more than 100 trillion times the mass of Earth's sun.
"Understanding how these enormous elliptical galaxies formed is one of the biggest open questions in modern astronomy and this is an important step in comprehending their history," said doctoral student Will Hartley, who led the study.
Hartley and others presented the findings last week in Belfast, Northern Ireland, during a Royal Astronomical Society meeting.