Astronomers have identified an extreme star-forming galaxy in the early universe.
The discovery was made using the Atacama Large Millimeter/submillimeter Array (ALMA). The galaxy, called Y1, lived between 600 and 800 million years after the Big Bang.
A team led by Tom Bakx from Chalmers University of Technology measured the temperature of Y1. They found it forming stars at around 180 solar masses per year. This is about 180 times the Milky Way’s star-formation rate.
The researchers used ALMA’s Band 9 at 0.44 mm along with its 66 radio antennas. They recorded dust in Y1 glowing at roughly 90 K, or about –180°C. Astronomer Yoichi Tamura said this warm dust confirms Y1 as “an extreme star factory”.
Y1, also known as MACS0416_Y1, lies at a redshift of about 8.3. Its star-formation rate is an intense and brief burst. Such hidden bursts may have been widespread in the early cosmos.
Other observations support this view.
The Webb telescope has found around 83 small starburst galaxies from a time 800 million years after the Big Bang. NASA says these small galaxies were powerful enough to contribute to cosmic reionisation, as noted by Isak Wold.
Another example comes from ALMA and JWST data. They detected a barred spiral galaxy called J0107a. It was nearly 10 times the mass of the Milky Way. It formed stars at a rate about 300 times higher. These findings suggest that hidden starbursts shaped galaxies in the universe’s first billion years.