Astronomers have made a groundbreaking discovery using data from the James Webb Space Telescope, revealing over a dozen “dormant” galaxies in the early universe that stopped forming new stars within the first billion years after the Big Bang. This finding sheds light on how early galaxies grow and could provide clues about galaxy evolution.
The discovery was made possible by the telescope’s sensitive spectroscopic data, which allowed researchers to identify 14 dormant galaxies with a wide range of masses. These galaxies, including three with masses below one billion solar masses and one with a mass above 10 billion solar masses, are thought to have paused their star formation due to various reasons such as supermassive black holes or stellar feedback.
The team used publicly available galaxy data in the DAWN JWST Archive to examine the light of about 1,600 galaxies, looking for signs of new stars not forming. They found that all 14 galaxies had halted star formation between 10 million and 25 million years before observation, suggesting a stop-and-go fashion of star formation rather than continuous star formation.
While the exact cause of quenching remains uncertain, the researchers believe that stellar feedback, such as supernovas or stellar winds, may have caused these galaxies to go quiet. However, if they remain dormant for another 50 million years, it would suggest a different cause and potentially indicate that the galaxy is dead.
The discovery has sparked hope that future observations will help shed light on these “snoozing star factories.” An upcoming JWST program called “Sleeping Beauties” will focus on discovering dormant galaxies in the early universe, allowing astronomers to estimate how long a galaxy remains in this quiet phase and understand the bursty star formation process.
Source: https://www.space.com/astronomy/james-webb-space-telescope/james-webb-telescope-reveals-sleeping-beauty-galaxies-in-the-early-universe-snoozing-where-they-werent-supposed-to-exist