The centre of the galaxy, in radio-vision

From Earth’s position out on the periphery of the Milky Way, it can be hard to peer through the clouds of dust and gas that shroud the centre of the galaxy to get a decent view. One way around that problem is to look in a different part of the electromagnetic spectrum: the long wavelengths of radio waves, for instance, pass straight through.

The MeerKAT radio telescope in South Africa has done just that, providing the clearest radio image yet of the galaxy’s central region. 

Built and operated by the South African Radio Astronomy Observatory (SARAO), and a decade in design and construction, MeerKAT has just begun its science operations. At the opening, a stunning new panorama obtained by the telescope was unveiled, revealing extraordinary detail in the region surrounding the supermassive black hole at the centre of our Milky Way.

MeerKAT is an array of 64 dishes. The signals from all 64 are combined across 2000 unique antenna pairs, far more than any comparable telescope, resulting in high-fidelity images of the radio sky. Eventually, MeerKAT will become part of the even larger Square Kilometre Array (SKA) radio telescope, which will also have dishes in Western Australia.

The image clearly shows mysterious filamentary structures present near the central black hole but nowhere else in the Milky Way. These long and narrow magnetized filaments were discovered in the 1980s using the Very Large Array (VLA) radio telescope in New Mexico, but their origin has remained a mystery.