Astronomers have stumbled upon a fascinating discovery: a superheated “star factory” called Y1. This galaxy dates back just 800 million years after the Big Bang and is churning out stars at an astonishing rate—180 times faster than our Milky Way. Understanding Y1 can shed light on how galaxies expanded so rapidly in the early universe.
Researchers studied Y1 by analyzing the cosmic dust’s temperature using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. This advanced telescope allowed them to capture light from the galaxy that’s traveled to Earth for 13 billion years.
Team leader Tom Bakx, from Chalmers University in Sweden, highlighted the importance of this discovery. “We’re looking back at a time when stars formed much faster than they do today,” he explained. They had already detected dust in Y1, making it the most distant galaxy from which we’ve directly observed glowing dust. To confirm their hypothesis, they measured its temperature.
This research is part of a broader goal to understand the first stars, known as Population III (POP III) stars. Conditions during their formation were likely very different from today’s stars, like those in our solar system.
Stars are typically born in dense regions of gas and dust, like the Orion and Carina Nebulae. These areas glow due to the light from young, massive stars. Bakx noted, “When we observed Y1, we could tell we were looking at something extraordinary due to its brightness at certain wavelengths.” ALMA’s sensitivity was crucial in making this discovery, revealing that Y1’s dust glows at around minus 356 degrees Fahrenheit (minus 180 degrees Celsius).
Despite being chilly compared to Earth’s dust, Y1’s temperature is warmer than other similarly observed galaxies. Team member Yoichi Tamura from Nagoya University remarked that this finding confirmed Y1 as an extreme star factory. “There could be many more galaxies like Y1 in the early universe,” he added.
Y1’s rapid star production, around 180 solar masses a year as observed, suggests that intense star formation phases might have been common in early galaxies. However, these bursts are likely short-lived in cosmic terms.
Bakx expressed a desire to find more examples of such star factories in the future. “We plan to use ALMA’s capabilities to explore how this galaxy operates,” he said.
Further research on Y1 may help solve an ongoing mystery about early galaxies. Previous studies indicate that these galaxies seem to have more dust than expected, given their young age and lack of older stars needed for dust formation. Laura Sommovigo from the Flatiron Institute and Columbia University explained that warm, bright dust can mimic larger amounts of cooler dust. “What we’re observing in Y1 fits this pattern,” she noted, emphasizing the intriguing nature of these young galaxies.
This groundbreaking study was published in the Monthly Notices of the Royal Astronomical Society on November 12. Understanding galaxies like Y1 could reshape our knowledge of cosmic evolution and star formation.
