The MeerKAT radio telescope array is finally up and running in South Africa, after a decade of design and construction. To show off what the facility can do, astronomers have pointed all 64 antennas towards the center of the Milky Way galaxy, and snapped one of the clearest shots ever taken of the mysterious region.
MeerKAT is made up of 64 dishes each measuring 13.5 m (44.3 ft) in diameter, spaced up to 8 km (5 mi) apart and spread across the dusty Karoo region of South Africa. It's operated by the South African Radio Astronomy Observatory (SARAO) and is just the first phase of the Square Kilometer Array, a project that will eventually form the largest telescope in the world with facilities in Africa and Australia.
"We wanted to show the science capabilities of this new instrument," says Fernando Camilo, chief scientist of SARAO. "The center of the galaxy was an obvious target: unique, visually striking and full of unexplained phenomena – but also notoriously hard to image using radio telescopes. Although it's early days with MeerKAT, and a lot remains to be optimized, we decided to go for it – and were stunned by the results."
The center of the Milky Way is difficult to see from Earth, thanks to thick clouds of dust and gas in the way, but radio telescopes are able to peer through. With 64 antennas trained on the area making up 2,000 unique pairs of "eyes," MeerKAT was able to capture the region in unprecedented detail.
The end result of MeerKAT's observations is a panorama shot spanning an area of about 1,000 light-years by 500 light-years. The colors show the strength of the received radio signals, going from red for faint emissions, up to orange, then yellow, to white for the brightest sources.
Unsurprisingly, the brightest part of the image is that surrounding the supermassive black hole at the very center of the galaxy. Other bright spots indicate supernova remnants and star-forming regions, some of which have never been imaged before, while others are simply seen more clearly than they have in the past.
The other key feature is the magnetized "filament" structures that shine bright as radio signals. These formations don't seem to exist anywhere else in the galaxy, and although they were first discovered in the 1980s we still don't know much about them.
"The MeerKAT image has such clarity," says Farhad Yusef-Zadeh, an astronomer from Northwestern University. "It shows so many features never before seen, including compact sources associated with some of the filaments, that it could provide the key to cracking the code and solve this three-decade riddle."
This isn't MeerKAT's first image. Two years ago the array revealed over 1,300 new galaxies in one patch of sky, using just 16 of its antennas. Now that MeerKAT is properly up and running, it will scour the skies over the Southern Hemisphere for signs of gravitational waves, pulsar signals and may even contribute to the search for signs of extraterrestrial intelligence.
Source: Square Kilometer Array Africa