Tuesday 01 July 2025
A halo of mystery surrounds our galaxy’s centre, and scientists have finally cracked open a piece of this enigmatic puzzle. By studying the HI absorption patterns around Sgr A*, the supermassive black hole at the heart of the Milky Way, researchers have discovered that the 7′ halo, a region of radio emission surrounding the galactic centre, is indeed located at the same distance as the +50 km/s molecular cloud associated with Sgr A*.
For years, astronomers have been fascinated by the 7′ halo’s peculiar properties. Its unusual size and shape, combined with its intense radio emission, make it an intriguing target for study. But despite numerous observations, the halo’s distance from us remained a mystery. Some theories suggested that it might be closer to us, while others proposed it could be much farther away.
The latest research, published in a recent scientific paper, uses HI absorption data to shed light on this puzzle. The team analyzed archival radio observations of the 7′ halo and found strong HI absorption signatures at velocities consistent with the +50 km/s molecular cloud. This cloud is believed to be associated with Sgr A*, making it an important clue in understanding the galaxy’s centre.
The findings suggest that parts of the 7′ halo are indeed behind the +50 km/s molecular cloud, while other regions may be closer to us. This discovery has significant implications for our understanding of the galactic centre’s structure and evolution. It also raises new questions about the origins of the 7′ halo itself.
One possibility is that the halo was created by energetic events in the galaxy’s past, such as supernovae or other massive explosions. These outbursts could have injected energy into the surrounding interstellar medium, leading to the formation of the 7′ halo. Another theory suggests that the halo might be a remnant of a previous era of starburst activity in the galactic centre.
The study’s results also hint at a complex and dynamic environment around Sgr A*. The presence of multiple velocity components within the 7′ halo, combined with the absorption signatures, suggests that gas and dust are being swept up by strong winds or outflows emanating from the black hole. This turbulent environment could be responsible for shaping the galaxy’s centre over millions of years.
The discovery of the 7′ halo’s distance has far-reaching implications for our understanding of the Milky Way’s evolution.
Cite this article: “Unveiling the Secrets of the Galactic Centre’s Enigmatic Halo”, The Science Archive, 2025.
Galaxy Centre, Supermassive Black Hole, 7′ Halo, Radio Emission, Hi Absorption, Molecular Cloud, Sgr A*, Milky Way, Galactic Evolution, Starburst Activity
