Deep in the heart of our Galaxy lies one of the most chaotic and mysterious regions in space. Now, scientists have created the first detailed map of magnetic fields in this turbulent zone, providing crucial insights into how stars form and evolve in extreme environments.
The research, led by University of Chicago PhD student Roy Zhao, focused on a region called Sagittarius C, located in the Central Molecular Zone near the centre of the Milky Way. This area serves as what researchers call an astrophysical “Rosetta Stone”, an area key to understanding the complex interactions between dense gas clouds, star formation, and powerful magnetic fields that shape our Galaxy.
The Galactic center and the surrounding Central Molecular Zone. Molecular Hydrogen gas is shown here as purple while cold dust associated gas is orange. (Credit : NRAO/AUI/NSF)
The team used NASA’s now retired flying telescope SOFIA to study infrared light emitted by tiny dust grains scattered throughout the region. These microscopic particles act like compasses, aligning themselves with magnetic field lines and by analysing the polarised light they emit, it’s possible to map the invisible magnetic fields for the first time.
SOFIA, Flying Infrared Observatory (Credit : NASA/Jim Ross)
What they discovered was remarkable. The magnetic field wraps around an expanding bubble of hot, electrified gas that has been blown outward by the powerful winds from a cluster of massive young stars. This bubble structure helps explain one of the Galaxy’s most puzzling features, thin streams of high speed electrons that race through space at nearly the speed of light.
These mysterious radio emitting filaments were first discovered in the 1980s by Zhao’s advisor, Professor Mark Morris, but their origin remained unclear. The new magnetic field measurements support the leading theory that these electron streams form when magnetic field lines collide and reconnect, accelerating nearby particles to incredible speeds.
The findings reveal how different components of our Galaxy interact in this extreme environment. Cold gas clouds where new stars are born, hot ionised regions heated by stellar winds, and powerful magnetic fields all influence each other in a cosmic ballet that determines the fate of matter in our Galaxy’s centre.
Perhaps most surprisingly, the research showed how different astronomical surveys of the same region tell a consistent story. The magnetic field boundaries perfectly matched observations of ionised carbon emissions from another study, and the team even identified a specific type of massive star called a Wolf-Rayet star at the centre of the expanding bubble.
James Webb Space Telescope image of the Wolf–Rayet star WR 124 and the nebula M1–67 surrounding it. NIRCam and MIRI composite. (Credit : NASA, ESA, CSA, STScI, Webb ERO Production Team)
This study helps astronomers understand not just our own Galaxy, but similar processes occurring in galaxies throughout the universe. By studying this galactic Rosetta Stone, scientists can decode the fundamental physics governing how galaxies evolve, how stars form in extreme environments, and how magnetic fields shape the structures we see today.
Source : Galactic Rosetta Stone