A recent study by researchers from the University of Southampton, in collaboration with international experts, has pinpointed the birthplaces of massive elliptical galaxies. These findings provide valuable insights into their formation.

Unlike our disk-shaped Milky Way, these ancient galaxies resemble bulging footballs, and their origins have long remained elusive. However, new research suggests that massive flows of cold gas and galactic collisions in the early universe played a critical role in creating these colossal systems.

"Two disk galaxies colliding caused gas - the raw material for star formation - to concentrate at their centers, resulting in the creation of trillions of new stars," explained Dr. Annagrazia Puglisi from the University of Southampton, a co-author of the study. "These cosmic events occurred approximately 8 to 12 billion years ago, during an era when the universe was much more active."

The study, published in Nature, involved experts from the Purple Mountain Observatory in China, the Chinese Academy of Sciences, and other institutions. The team analyzed over 100 star-forming galaxies in the distant universe using the Atacama Large Millimeter/submillimeter Array (ALMA), the world's largest radio telescope located in Chile.

Using a novel technique, the researchers examined light distributions emitted by distant and highly luminous galaxies. "This is the first concrete evidence that spheroids form directly through intense star formation episodes occurring in the cores of remote galaxies," said Dr. Qing-Hua Tan from the Purple Mountain Observatory, who led the study.

She added, "For decades, astrophysicists have sought to understand this process. These galaxies form rapidly, as gas is drawn inward to feed black holes, triggering starbursts at rates 10 to 100 times faster than in the Milky Way."

The team relied on open-source A3COSMOS and A3GOODSS archives to collect high-quality observations of distant galaxies. Their next steps include integrating their findings with data from the James Webb Space Telescope (JWST), the Euclid satellite, and the Chinese Space Station to map galaxies' stellar structures in greater detail.

Dr. Puglisi noted, "This approach will provide a more complete picture of early galaxy formation and enhance our understanding of how the universe has evolved since its inception."

Research Report:In situ spheroid formation in distant submillimetre-bright Galaxies

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