A mysterious neutrino signal has led astronomers to a surprising discovery: a hidden star-forming galaxy, not a supermassive black hole, may be generating some of the Universe’s most powerful particles.
Astronomers have traced a burst of high-energy neutrinos to an unexpected source. Using the Atacama Large Millimeter/submillimeter Array (ALMA) and a powerful natural magnifying effect created by gravity, researchers investigated a remarkably bright distant galaxy. They initially suspected that a supermassive black hole was powering the galaxy. Instead, they found evidence that intense star formation was driving its activity. The discovery provides important clues about the origin of cosmic neutrinos, one of the Universe’s most mysterious particles.
Neutrinos are among the most elusive signals that reach Earth from space. Although a handful of galaxies have already been linked to neutrino production, those known sources cannot account for the large number of high-energy neutrinos detected by observatories.
Tracking the Source of a Neutrino Event
An international team of researchers from MITOS Science Co., LTD., National Central University, Chung Yuan Christian University, Tohoku University, Fukui University of Technology, and the National Astronomical Observatory of Japan conducted follow-up observations of a high-energy neutrino event known as IC 210922A. The event was originally detected by the IceCube Neutrino Observatory at the South Pole.
Using ALMA and other telescopes, the team searched for the source of the signal and identified an exceptionally luminous galaxy called JCMT0402−0424. The galaxy is located roughly 11 billion light-years from Earth.
Previously identified neutrino-producing galaxies have all been associated with supermassive black holes. However, the observations of JCMT0402−0424 revealed no signs of the energetic emissions typically produced by such objects.
The galaxy is also heavily veiled by dust, making it difficult to observe in visible light. At submillimeter wavelengths, however, it shines brightly. Because of its hidden nature, the researchers gave it the nickname ‘Shadow Blaster.’
A Natural Telescope Reveals the Galaxy’s Interior
The team was able to examine Shadow Blaster in remarkable detail thanks to a fortunate cosmic alignment. A galaxy located between Earth and Shadow Blaster acted as a gravitational lens. Its gravity bent and amplified radio waves coming from the distant galaxy, effectively creating a natural telescope that produced brighter and enlarged images for ALMA to study.
ALMA’s observations of the galaxy’s interior again failed to reveal evidence of a powerful black hole. Instead, the data pointed toward another explanation. The researchers concluded that the gas and dust within the galaxy are most likely being heated by extremely intense star formation.
Further analysis uncovered a dense “compact core” at the center of Shadow Blaster. Vast amounts of gas and dust are concentrated within a region only about 1,500 light-years across. Such extraordinarily dense conditions are capable of producing neutrinos.
A New Explanation for Cosmic Neutrinos
The findings suggest that high-energy neutrinos can be generated through a different process than previously recognized. Rather than relying primarily on supermassive black holes, some neutrinos may originate in compact, dust-rich starburst galaxies undergoing intense episodes of star formation.
Researchers estimate that these galaxies could account for a substantial share of the high-energy neutrino background, potentially contributing as much as 20% of the total population observed across the Universe.
Reference: “Compact dusty starbursts at cosmic noon linked to high-energy neutrinos” by Yuji Urata, Kuiyun Huang, Bunyo Hatsukade, Mansi Kasliwal, Shigeo S. Kimura, Yuichi Matsuda, Yusuke Miyamoto, Hiroshi Nagai, Kouichiro Nakanishi and Robert Stein, 17 June 2026, Nature Astronomy.
DOI: 10.1038/s41550-026-02884-9
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