Reviewed by Lexie CornerDec 5 2024
In collaboration with specialists from around the world, researchers from the University of Southampton suggest that their latest investigation may answer the long-standing mystery of how the largest galaxies in the universe form. The study was published in the journal Nature.
Two antennae galaxies colliding. Image Credit: NASA
Scientists have identified the birthplaces of massive elliptical galaxies, offering new insights into their formation.
Astrophysicists have long been puzzled by the origins of these ancient galaxies, which have a rounded shape compared to the Milky Way's flat disk. Dr. Annagrazia Puglisi of Southampton, co-author of the study, suggests that these giant systems were likely formed in the early universe through galaxy collisions and massive flows of cold gas.
Two disk galaxies smashing together caused gas–the fuel from which stars are formed–to sink towards their center, generating trillions of new stars. These cosmic collisions happened some eight to 12 billion years ago when the universe was in a much more active phase of its evolution. Our findings take us closer to solving a long-standing mystery in astronomy that will redefine our understanding of how galaxies were created in the early universe.
Dr. Annagrazia Puglisi, Study Co-Author, University of Southampton
Scientists from the University of Southampton, the Purple Mountain Observatory in China, and the Chinese Academy of Science collaborated on this research.
Experts used the ALMA, the largest radio telescope in the world, situated in Chile's Atacama desert, to analyze over 100 star-forming galaxies in the distant universe.
Dr. Qing-Hua Tan, the lead researcher from the Purple Mountain Observatory, explained that the discovery was made using a novel method to examine the distribution of light emitted by distant, extremely bright galaxies.
This is the first real evidence that spheroids form directly through intense episodes of star formation located in the cores of distant galaxies. Astrophysicists have sought to understand this process for decades. These galaxies form quickly; gas is sucked inwards to feed black holes and triggers bursts of stars, which are created at rates ten to 100 times faster than our Milky Way.
Dr. Qing-Hua Tan, Study Lead, University of Southampton
Researchers used the open-source A3COSMOS and A3GOODSS archival projects to collect high-quality observations of numerous distant galaxies.
To map the stellar components of galaxies, the scientists plan to integrate their findings with information obtained from telescopes on the Chinese Space Station, the JWST, and the Euclid satellites.
Dr. Puglisi from Southampton added: “This will give us a more complete picture of early galaxy formation and deepen our understanding of how the universe has evolved since the beginning of time.”
Journal Reference:
Tan, Q.-H., et al. (2024) In situ spheroid formation in distant submillimetre-bright galaxies. Nature. doi.org/10.1038/s41586-024-08201-6.