An unprecedentedly detailed image of the swirling gases forming stars at the heart of our Milky Way galaxy has been revealed by a telescope network in Chile. The image, released Wednesday by the European Southern Observatory (ESO), focuses on a region of cold cosmic gas spanning more than 650 light-years in diameter – approximately 6 billion billion kilometers, according to ESO.
The newly released mosaic depicts the central molecular zone (CMZ), a region surrounding the supermassive black hole Sagittarius A* at the galaxy’s center. The image showcases a complex network of dense gas and dust clouds, some stretching for decades of light-years, and smaller gas clouds enveloping individual stars. This is the largest image ever produced by the Atacama Large Millimeter/submillimeter Array (ALMA), located in the arid Atacama Desert of Chile.
ALMA observes the universe in millimeter and submillimeter wavelengths, which can penetrate the dust that obscures the galactic center, allowing astronomers to observe previously hidden structures. The data for the image was gathered by ALMA’s 66 high-precision antennas, which function as a single telescope with an effective diameter of 16 kilometers. The network was inaugurated in 2013 and is co-managed by ESO, the United States, and Japan.
“It’s an extreme environment, invisible to our eyes, but which is now being revealed with extraordinary detail,” said Ashley Barnes, a researcher with the European Southern Observatory, in a statement. The image is a product of the Atacama COmmissioning and Early Science (ACES) program, a mapping project dedicated to charting the core of the Milky Way.
According to Steve Longmore, lead researcher of the study at Liverpool John Moores University, studying star formation within the CMZ can provide insights into the evolution of galaxies. The region’s extreme conditions offer a unique laboratory for understanding the processes that govern star birth and galactic development. More than 160 scientists from 70 institutions worldwide collaborated on the project, including students, researchers, and retirees.
The observations build on previous infrared mapping of the Milky Way, including a detailed infrared map created from 200,000 images captured by the Visible and Infrared Survey Telescope for Astronomy (VISTA), also located in Chile. That map, completed between 2010 and 2023, cataloged over 1.5 billion celestial objects, revealing stars, brown dwarfs, and even rogue planets previously hidden from optical telescopes. (sciencepost.fr)
The new ALMA image provides a complementary view, penetrating the dust and gas to reveal the underlying structure and dynamics of the CMZ. Scientists have also observed stars launched at extreme speeds after close encounters with the supermassive black hole at the galaxy’s center, a rare phenomenon that highlights the powerful gravitational forces at play. (franceinfo.fr)
