Astronomers have just captured the most detailed, colossal image ever made of the centre of our galaxy, revealing a tangled web of previously hidden gas and chemistry swirling near the Milky Way’s supermassive black hole.
The extraordinary picture was taken with the powerful Atacama Large Millimeter/submillimeter Array (ALMA) — a network of radio telescopes high in Chile’s Atacama Desert — and spans more than 650 light-years across, making it the largest image ALMA has ever produced.
“It’s a place of extremes, invisible to our eyes, but now revealed in extraordinary detail,” said astronomer Ashley Barnes of the European Southern Observatory (ESO), one of the scientists behind the survey.
Hidden Chemistry and Star-Making Gas
Credit: ALMA(ESO/NAOJ/NRAO)/S. Longmore et al. Background: ESO/D. Minniti et al.
This new mosaic exposes the cold molecular gas — the raw fuel for star formation — threading through the Milky Way’s core in fine detail, from filaments dozens of light-years long down to clouds surrounding individual stars.
For the first time, researchers can see a rich mix of molecules — from simple compounds like silicon monoxide to more complex organic molecules such as methanol, acetone and ethanol — lurking in the Central Molecular Zone (CMZ) of our galaxy.
These cold streams of gas are believed to feed dense clumps out of which new stars grow. While scientists understand how this happens in calmer galactic regions, conditions near the Milky Way’s centre are far more chaotic due to the intense gravity and radiation from countless massive stars and the supermassive black hole.
A Glimpse into the Early Universe
The heart of our galaxy may be extreme, but that’s exactly what makes it so valuable. “By studying how stars are born in the CMZ, we can also gain a clearer picture of how galaxies grew and evolved,” said Steve Longmore, leader of the survey. Some features in this region resemble conditions thought to be common in early galaxies of the Universe.
Puzzle Pieces of the Cosmos
To create the massive image, astronomers stitched together dozens of individual observations — like assembling a cosmic puzzle — resulting in a map as wide as three full Moons placed side-by-side in the sky.
“This is only the beginning,” said ALMA scientist Katharina Immer. Future upgrades to ALMA and the upcoming Extremely Large Telescope (ELT) will let astronomers peer even deeper into this chaotic galactic heart, tracking chemical complexity and the dance of gas, stars and black holes with ever higher clarity.
Image Credit:
ALMA(ESO/NAOJ/NRAO)/S. Longmore et al. Stars in inset: ESO/D. Minniti et al. Milky Way: ESO/S. Guisard
