A team of astronomers has taken a crucial step to solve an enigma that has intrigued the scientific community for decades: the origin of giant elliptical galaxies, structures that began to form more than 12 billion years ago and that represent some of the largest entities of the universe.
According to research led by the University of Southampton, these colossal galaxies, whose shape resembles a balloon compared to the flat disks of systems such as the Milky Way, could have originated from collisions between disk galaxies. Dr. Annagrazia Puglisi, co-author of the study published in the journal Naturepoints out that these cosmic collisions had a determining role in the evolutionary history of the universe.
“When two disk galaxies collided, gas, the raw material for star formation, accumulated in their cores, generating trillions of new stars in explosive episodes of star formation,” Puglisi explained. These collisions occurred between 8,000 and 12,000 million years ago, during a highly active phase in the evolution of the cosmos.
To reach these conclusions, the scientists collaborated with the Purple Mountain Observatory and the Chinese Academy of Sciences. Using ALMA, the world’s largest radio telescope located in Chile’s Atacama Desert, they analyzed more than 100 star-forming galaxies at extremely distant distances.
Dr. Qing-Hua Tan, leader of the study, stressed that this research provides the first direct evidence that galactic “spheroids” are formed by intense episodes of star formation concentrated in the nuclei of distant galaxies. “These galaxies develop at a dizzying pace. “Gas is drawn inward to feed black holes, which in turn triggers star formation rates 10 to 100 times those of our Milky Way.”
The team also plans to combine their findings with data from space telescopes such as the James Webb, Euclid and observatories on the Chinese Space Station, to map in detail the stellar components of these early galaxies. According to Puglisi, this approach will allow us to obtain a more complete view of how galaxies formed in the early moments of the universe, providing essential clues to understand their evolution throughout the 13.8 billion years of existence of the cosmos.
The research not only redefines our view of elliptical galaxies, but also sheds light on the violent and dynamic processes that shaped the universe in its early chapters, when cosmic collisions were the norm rather than the exception.
by RN
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