A team of astronomers has taken a crucial step towards solving 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 which represent some of the largest entities in the universe planet.
According to research conducted 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, may have originated from collisions between disk galaxies. Dr. Annagrazia Puglisi, co-author of the study published in the journal Natureemphasizes that these cosmic collisions have played a decisive 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 very active phase in the evolution of the cosmos.
To reach these conclusions, scientists collaborated with the Purple Mountain Observatory and the Chinese Academy of Sciences. Using ALMA, the world’s largest radio telescope located in the Atacama Desert in Chile, they analyzed more than 100 star-forming galaxies at extremely distant distances.
Study leader Dr Qing-Hua Tan said 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 are developing at a dizzying pace. “Gas is pulled inward to fuel black holes, which in turn trigger 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 James Webb, Euclid and Chinese Space Station observatories to map the stellar components of these early galaxies in detail. According to Puglisi, this approach will allow us to obtain a more complete view of how galaxies formed in the first moments of the universe, providing essential clues to understand their evolution over 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
