An artistic illustration of rare ancient galaxies. Image credit: D. Berry/NRAO/AUI/NSF.

Astronomers discover rare ancient galaxy in deep space

Only a handful of these high-redshift (above 4.0) galaxies have been identified.


In a groundbreaking discovery, astronomers have unearthed a colossal, dormant galaxy, christened COSMOS-1047519. Utilizing the powerful Keck I telescope, they’ve revealed secrets that could reshape our understanding of the cosmos’ early days.

These massive, star-halted galaxies are considered precursors to the massive elliptical galaxies we see today. Their early star formation and rapid stellar mass assembly offer invaluable insights into the mysteries of galaxy progression. While only a handful of these high-redshift (above 4.0) galaxies have been identified, each discovery propels us closer to understanding the universe’s youthful phases.

A Massive Ancient Galaxy: COSMOS-1047519

Led by Takumi Kakimoto from Japan’s Graduate University for Advanced Studies, the team unveiled this massive quiescent galaxy, situated at a staggering redshift of 4.53, through the Keck/MOSFIRE spectrograph. Their study detailed a whopping 60 billion solar masses and a surprisingly low star-formation rate. At just 10 solar masses annually, and with a stellar age of around 180 million years, COSMOS-1047519 has undeniably old attributes for its age.


One fascinating discovery is COSMOS-1047519’s star-forming history. The team deduced it underwent a starburst phase around the redshift of 5.0. However, this intense activity was followed by a rapid, 100-million-year decline. This positions COSMOS-1047519 among the universe’s youngest dormant galaxies with a redshift surpassing 3.0. All signs point to a galaxy on the brink of stasis.

Decoding the Quenching Mystery

The question remains: What halted COSMOS-1047519’s star formation? The study’s authors suggest a riveting theory. The aftermath of a starburst or the influence of AGN (active galactic nuclei) feedback, potentially caused by galaxy interactions or mergers, might be the culprits behind this cessation.

COSMOS-1047519’s discovery underscores the complex dance of creation and cessation within our universe, hinting at the processes that shape galaxies’ destinies.


*NOTE: The featured image is an artistic illustration. 

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Written by Ivan Petricevic

I've been writing passionately about ancient civilizations, history, alien life, and various other subjects for more than eight years. You may have seen me appear on Discovery Channel's What On Earth series, History Channel's Ancient Aliens, and Gaia's Ancient Civilizations among others.

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