eso_eso2603a February 25th, 2026
Credit: ALMA(ESO/NAOJ/NRAO)/S. Longmore et al. Background: ESO/D. Minniti et al.
This image shows the complex distribution of molecular gas in the Central Molecular Zone (CMZ) of the Milky Way. It was obtained with the Atacama Large Millimeter/submillimeter Array (ALMA), in which ESO is a partner. This map is as long as three full Moons side-by-side in the sky, and it is in fact the largest ALMA image ever obtained. This map is part of ACES — the ALMA CMZ Exploration Survey — a project designed to understand how gas condenses into stars in the extreme and chaotic environment at the heart of our galaxy. The survey has charted the distribution of dozens of different molecules, five of which are shown here in different colours: sulphur monoxide (cyan), silicon monoxide (green), isocyanic acid (red), cyanoacetylene (blue), and carbon monosulphide (magenta). The stars in the foreground of this image were observed at infrared wavelengths (Y, Z and J filters) with ESO’s VISTA telescope as part of a different project. The actual density of stars in the CMZ is much higher than what is shown here, where we have opted to highlight the details in the molecular cloud. Note that the edges of the ALMA map appear somewhat sharp because the ALMA observations do not cover the entire rectangular area here.
Provider: European Southern Observatory
Image Source: https://www.eso.org/public/images/eso2603a/
Curator: European Southern Observatory, Garching bei München, None, Germany
Image Use Policy: Creative Commons Attribution 4.0 International License
Detailed color mapping information coming soon...
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