Astronomers Discover a Superheated Star Factory in the Early Universe
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Astronomers Discover a Superheated Star Factory in the Early Universe

12 November, 2025 / Read time: 3 minutes
Scientific Paper

Astronomers have uncovered a previously unknown, extreme kind of star factory by taking the temperature of a distant galaxy using the ALMA telescope. The galaxy is glowing intensely in superheated cosmic dust while forming stars 180 times faster than our own Milky Way. The discovery indicates how galaxies could have grown quickly when the universe was very young, solving a long-standing puzzle for astronomers.

The first generations of stars formed under conditions very different from anywhere we can see in the nearby universe today. Astronomers are studying these differences using powerful telescopes that can detect galaxies so far away their light has travelled towards us for billions of years.

Now, an international team of astronomers led by Tom Bakx at Chalmers University of Technology in Sweden has measured the temperature of one of the most distant known star factories. The galaxy, known as Y1, is so far away that its light has taken over 13 billion years to reach us.

Additional Information

This research is presented in the paper A warm ultraluminous infrared galaxy just 600 million years after the Big Bang in Monthly Notices of the Royal Astronomical Society, lead author Tom Bakx (Chalmers University of Technology, Sweden).

Read more in this press release from Chalmers University.

The Atacama Large Millimeter/submillimeter Array (ALMA), an international astronomy facility, is a partnership of the European Southern Observatory (ESO), the U.S. National Science Foundation (NSF), and the National Institutes of Natural Sciences (NINS) of Japan in cooperation with the Republic of Chile. ALMA is funded by ESO on behalf of its Member States, by NSF in cooperation with the National Research Council of Canada (NRC) and the National Science and Technology Council (NSTC) in Taiwan, and by NINS in cooperation with the Academia Sinica (AS) in Taiwan and the Korea Astronomy and Space Science Institute (KASI).

ALMA construction and operations are led by ESO on behalf of its Member States; by the National Radio Astronomy Observatory (NRAO), managed by Associated Universities, Inc. (AUI), on behalf of North America; and by the National Astronomical Observatory of Japan (NAOJ) on behalf of East Asia. The Joint ALMA Observatory (JAO) provides the unified leadership and management of ALMA's construction, commissioning, and operation.

Images

Glowing deep red from the distant past: galaxy Y1 shines thanks to dust grains heated by newly-formed stars (circled in this image from the James Webb telescope). Credit: NASA, ESA, CSA, STScI, J. Diego (Instituto de Física de Cantabria, Spain), J. D’Silva (U. Western Australia), A. Koekemoer (STScI), J. Summers & R. Windhorst (ASU), and H. Yan (U. Missouri)
Galaxy Y1 and its surroundings as seen by James Webb Space Telescope’s NIRCAM (blue and green) and by ALMA (red). Credit: NASA, ESA, CSA (JWST), T. Bakx/ALMA (ESO/NRAO/NAOJ)

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