Breakthrough Milky Way Image Exposes Hidden Chemistry At Galaxy's Core
Astronomers have captured the largest and most detailed image of the Milky Way’s core to date, revealing a chaotic web of cosmic filaments at our galaxy's center. Using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile, a research team mapped the Central Molecular Zone (CMZ), the star formation engine that spans more than 650 light-years.
This massive mosaic (shown above) provides an unprecedented look at the CMZ, home to the Milky Way’s most massive stars. Because the galactic center is shrouded by thick curtains of interstellar dust, radio wave telescopes have been our best bet for peering through this soup. That said, ALMA’s instruments have provided the richest data ever had on the CMZ, even revealing the cold molecular gas that serves as the raw building material for new stars.
The survey, known as ACES (ALMA CMZ Exploration Survey), has identified dozens of different molecules drifting through the central filaments. These range from simple compounds like silicon monoxide to complex organic ones such as methanol, acetone, and ethanol. These chemicals act as tracers, allowing astronomers to track the flow of gas as it streams into dense clumps where new stars eventually ignite. Analyzing these molecular signatures, the team can then map the temperature, density, and velocity of the gas more effectively than before.
No doubt, the survey shows that the CMZ is a busy place. Data shows everything from massive filaments dozens of light-years long down to tiny envelopes of gas surrounding individual budding stars. This kind of detail could prove useful in understanding why the center of our galaxy produces stars differently than the quieter outskirts. Studying the CMZ effectively allows astronomers to use our galaxy's center as a lab to understand how galaxies evolved billions of years ago.
The ACES project marks the first time such a large area of the galactic center has been scanned with this level of sensitivity, with the mosaic spanning as wide as three full moons. The research team believes this dataset will serve as a foundational map for decades, guiding future observations with the upcoming ESO Extremely Large Telescope and the ALMA Wideband Sensitivity Upgrade.
