Astronomers have made an extraordinary discovery using the James Webb Space Telescope, spotting the oldest “dead” galaxy ever observed. This finding provides a deep insight into the distant universe and raises questions about the factors that affect star formation within galaxies. The galaxy in question existed when the universe was only 700 million years old, but something caused it to abruptly halt star formation. The cause of this sudden stoppage remains a mystery.
The research team published their findings in the journal Nature, highlighting the significance of studying this galaxy in unraveling the mysteries of the early universe. Lead study author Tobias Looser, a doctoral student at the University of Cambridge’s Kavli Institute for Cosmology, explained that the early universe was a phase of intense activity, with gas clouds collapsing to form new stars. Galaxies require a rich supply of gas to continue forming stars, and during this early period, the universe was like an “all-you-can-eat buffet” for star formation.
The discovery of this “dead” galaxy challenges conventional understanding because it died so soon after the big bang. Typically, galaxies stop forming stars much later in the universe’s timeline. Dr. Francesco D’Eugenio, a study coauthor and astrophysicist at the Kavli Institute for Cosmology, expressed surprise at this finding. He noted that usually, galaxies stop forming stars due to black holes or other factors, but in this case, it occurred at an unexpectedly early stage.
The cessation of star formation in galaxies can be attributed to various factors. Environmental conditions can deprive a galaxy of the gas necessary for new star birth. Supermassive black holes or violent stellar interactions can eject gas from galaxies, abruptly halting star formation. Alternatively, the process of star birth can consume so much gas that there isn’t enough time for replenishment, leading to a halt in star formation. However, the researchers are unsure if any of these scenarios can explain what they observed with the Webb telescope.
Roberto Maiolino, a study coauthor and professor of experimental astrophysics at the University of Cambridge, emphasized the need to revisit current models of the early universe. Until now, scientists have relied on models based on the modern universe to understand the early universe. However, with the ability to observe much further back in time, it is clear that star formation was rapidly quenched in this particular galaxy. This discovery suggests that existing models may require revision.
The James Webb Space Telescope’s observations revealed that the newly discovered galaxy, named JADES-GS-z7-01-QU, experienced a brief but intense burst of star formation lasting between 30 million and 90 million years before abruptly ceasing. Lead study author Tobias Looser suggested that everything in the early universe seems to happen faster and more dramatically, including galaxies transitioning from a star-forming phase to a dormant state.
While this dead galaxy is not the first of its kind to be discovered, it is the oldest one observed thus far. What makes it even more intriguing is its low mass, similar to a dwarf galaxy near the Milky Way called the Small Magellanic Cloud, which is still actively forming stars. Previous dead galaxies that have been observed were much larger, adding another layer of peculiarity to this discovery.
The newly found galaxy is located billions of light-years away from Earth. The James Webb Space Telescope allows astronomers to observe it as it existed in the past. There is even a possibility that this galaxy may have resurrected and begun star formation again. The researchers are now searching for other galaxies like this one in the early universe to gain further insights into why and how galaxies stop forming stars. The possibility of galaxies “dying” and then bursting back to life remains an intriguing question that requires more observations to answer definitively.
This groundbreaking discovery opens up new avenues for understanding the early universe and the complex processes that govern star formation within galaxies. The James Webb Space Telescope continues to provide us with unprecedented views of the cosmos, pushing the boundaries of our knowledge and inspiring further exploration. As we delve deeper into the mysteries of the universe, we may uncover even more surprises that challenge our existing theories and expand our understanding of the cosmos.
