Ancient Galaxy Collisions May Explain Formation of Massive Early Star Systems

The origins of the universe's largest galaxies, long a mystery to astronomers, may have been revealed by a new study published in Nature on December 4. Researchers have suggested that cosmic collisions between galaxies billions of years ago could have created the most massive star systems. These galaxies, unlike the Milky Way's flat spiral shape, exhibit a spherical, bulging structure. According to the findings, these collisions likely took place when the universe was just 1 to 5 billion years old and were marked by intense bursts of star formation.

Key Observations Made Using ALMA

Observations made by the Atacama Large Millimeter/submillimeter Array (ALMA) in northern Chile played a crucial role in this research. A team led by Qing-Hua Tan of the Purple Mountain Observatory examined the light distribution from over 100 distant galaxies. These galaxies, identified in archival data from the A3COSMOS and A3GOODSS projects, were studied for their extreme star-forming activity.

Tan stated to Nature that direct evidence has been found indicating that these spheroidal galaxies formed through episodes of intense star formation at their cores. The study demonstrates how gas, drawn toward the centres of colliding galaxies, facilitated the creation of stars at rates significantly exceeding those of the Milky Way.

Insights into Early Universe Evolution

University of Southampton researcher Anna Puglisi, part of the team, explained to Nature that these processes occurred 8 to 12 billion years ago, during a period when the universe experienced heightened activity. The study marks a significant step toward understanding early galactic evolution.

As per reports, the researchers plan to integrate their findings with data from the James Webb Space Telescope and the Euclid satellite to map star populations within these galaxies. According to Puglisi, in a statement, this combined analysis could provide a more comprehensive understanding of how galaxies formed and evolved in the universe's early stages.