Astronomers have found that collisions between galaxies in the early universe created large flows of cold gas, leading to the formation of some of the most massive star systems. The creation of ancient massive galaxies with bulging shapes, unlike our flat spiral galaxy, the Milky Way, has puzzled astronomers for years.
A team led by researchers from the University of Southampton believes that their research may provide answers to this long-standing galactic mystery. They suggest that two disk galaxies colliding caused gas, the building block of stars, to move towards their center, producing trillions of new stars. These cosmic collisions occurred 8 to 12 billion years ago when the universe was much more active.
Published in the journal Nature on December 4, the team used the Atacama Large Millimeter Array (ALMA) to gather high-quality observations of distant galaxies. They analyzed over 100 galaxies actively forming stars and used a new technique to study the light distribution from these bright galaxies.
Qing-Hua Tan from the Purple Mountain Observatory explained that their project revealed evidence that spheroids form through intense star formation episodes in the cores of distant galaxies. These galaxies form rapidly, with gas being drawn in to fuel black holes and trigger rapid bursts of star creation.
The team plans to combine their findings with data from the James Webb Space Telescope (JWST) and the Euclid satellite to further investigate early galaxy formation and understand how the universe has evolved.
“This research brings us closer to solving a longstanding mystery in astronomy and will enhance our knowledge of early galaxy formation,” concluded Anna Puglisi, a researcher at the University of Southampton.
