Astronomers have unveiled the most detailed view yet of the turbulent heart of the Milky Way, capturing an extraordinary web of cosmic gas filaments swirling around the galaxy’s central black hole.
The stunning new image, produced using the Atacama Large Millimetre/submillimeter Array (ALMA), represents the largest dataset ever obtained by the observatory.
The image reveals the Central Molecular Zone (CMZ), a dense, chaotic region of cold molecular gas stretching more than 650 light-years across. This area surrounds the Milky Way’s supermassive black hole and contains the raw material from which new stars are born. For the first time, astronomers have mapped the cold gas across the entire CMZ in unprecedented detail.
“It’s a place of extremes, invisible to our eyes, but now revealed in extraordinary detail,” said Ashley Barnes of the European Southern Observatory (ESO), a member of the international research team.
The observations were conducted as part of the ALMA CMZ Exploration Survey (ACES), led by Steve Longmore of Liverpool John Moores University. The survey focuses on cold molecular gas, the fundamental building block of star formation.
Using ALMA’s powerful radio capabilities, scientists detected dozens of molecules within the region, including silicon monoxide and more complex organic compounds such as methanol, acetone and ethanol.
The dataset exposes a complex network of filaments channelling gas into dense clumps where stars begin to form. While star formation processes are relatively well understood in the calmer outskirts of the galaxy, conditions near the galactic centre are far more extreme.
The CMZ hosts some of the Milky Way’s most massive stars, many of which burn brightly and briefly before exploding as supernovae or even hypernovae.
Researchers believe this region mirrors the chaotic environments seen in early galaxies billions of years ago. By studying star birth in such an intense setting, astronomers hope to refine existing models of how galaxies grow and evolve.
The massive mosaic image was created by stitching together numerous individual observations, spanning an area in the sky equivalent to three full Moons placed side by side. According to the team, the sheer complexity of the structures revealed exceeded expectations.
The findings have been detailed in five papers accepted for publication in the Monthly Notices of the Royal Astronomical Society, with another currently under review.
With planned upgrades to ALMA and the future Extremely Large Telescope, astronomers say this groundbreaking survey marks only the beginning of deeper explorations into the dynamic heart of our galaxy.
