The study, published in the journal Nature, looked at galaxies that existed when the universe was only about 1 billion years old. These galaxies are thought to be the progenitors of the present-day Milky Way and other large galaxies.
The researchers found that these early galaxies were far more efficient at converting gas into stars than present-day galaxies. They also found that the galaxies were more compact and had higher star formation rates.
The study's lead author, Erica Nelson of the University of Colorado Boulder, said that the findings suggest that the early universe was a much more dynamic and rapidly changing place than previously thought.
"The early universe was a time of incredible transformation," Nelson said. "Galaxies were evolving at an incredibly rapid pace, and the universe was a very different place than it is today."
The study's findings could help to shed light on how the first galaxies formed and evolved. The researchers believe that the early galaxies may have been influenced by interactions with other galaxies or by inflows of gas from the intergalactic medium.
The study also has implications for our understanding of the universe's expansion. The researchers found that the early galaxies were more compact than present-day galaxies, which suggests that the universe may have expanded more slowly in the early stages of its evolution.
The study's findings are based on data from the Hubble Space Telescope's Cosmic Origins Survey (COSMOS). The COSMOS survey is a large-scale survey of the universe that has imaged over 2 million galaxies.
