Researchers have used an ultra-sensitive camera attached to a giant high-altitude balloon to capture light from the centre of the Milky Way. The galactic centre is known to emit high-energy gamma rays, but the exact astrophysical source of this radiation remains unidentified. The balloon-borne instrument was designed to detect these high-energy particles with greater sensitivity than previous efforts.
The experiment, led by T. Ikeda and colleagues, is reported in Physical Review D. By operating above most of the Earth's atmosphere, the balloon platform reduces background interference that complicates ground-based gamma-ray observations. This vantage point allows the camera to gather clearer data on the diffuse emission coming from the galactic core.
The new dataset provides a fresh observational window on the central region of the galaxy. Scientists hope the improved measurements will help distinguish between competing theories for the gamma-ray excess, which include dark matter annihilation, a population of unresolved pulsars, or other high-energy astrophysical processes.
Previous observations from space-based telescopes and ground-based arrays have mapped the gamma-ray sky, but the specific origin of the central emission has persisted as an open question. The balloon flight offers a complementary approach, combining the low atmospheric background of space missions with the ability to deploy large, upgradable instruments.
The research highlights the continuing role of suborbital platforms in fundamental astrophysics. Balloon-borne experiments can test cutting-edge detector technology and target specific science goals on shorter timescales and lower budgets than satellite missions.
Further analysis of the collected data is required to determine whether the new observations can resolve the source of the gamma rays. The collaboration plans to refine their instrument and conduct additional flights to build statistical significance.
The study demonstrates that high-altitude balloons remain a viable platform for probing the most energetic processes in the galaxy. Results from this flight will inform the design of future experiments, both suborbital and space-based, aimed at solving the mystery of the galactic centre's high-energy glow.
Giant balloon gives rise to new view of the Milky Way’s centre
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