In its first major result, just over a year after its discovery, a super sensitive South African telescope detected two giant "radio bubbles" above and below the central Milky Way area. The characteristics extend to a total of 430 parsecs (1400 light-years), about 5% of the distance between the solar system and the center of the galaxy.
Bubbles are gaseous structures that can be observed because electrons stirring inside produce radio waves as they are accelerated by magnetic fields. This activity suggests that bubbles are the remnants of a vigorous burst of hot gas several million years ago, according to the authors of a paper describing the characteristics published in Nature on September 1
One possible explanation is that a supermassive black hole in the center of the galaxy underwent a period of intense material trapping that created the outbreak, researchers say. Another could be a "star burst" – the almost simultaneous formation and subsequent fiery death of about 100 big stars. The shock waves from their explosions could be combined to punch a hole through the dense interstellar matter of the central region of the Galaxy.
Oliver Pful, an astronomer at the European Southern Observatory in Gurching, Germany, says that both stellar shot and black hole activity may have played out, even intensifying. And the researchers are aware of a stellar explosion that took place in the region about 7 million years ago. "It's intriguing to associate a radio balloon with this star-forming event," he says.
Researchers working with the MeerKAT Radio Telescope in South Africa – a harbinger of the largest radio telescope in the world, the Square Kilometer (SKA) "They discovered bubbles when they created an image of the Galactic Center to celebrate the observatory's opening and to celebrate. its brand new facility in early April 2018, says radio astronomer Fernando Camilo, the observatory's chief scientist. It usually takes years for researchers to get a new observatory that works properly and produces science with it. But with MeerKAT, they were amazed at how smoothly things were going. "It worked straight," Camillo says.
Bubbles can also solve an old puzzle in radio astronomy. The electrons accelerating inside them may be the source of bright "filaments" of matter, the long dozens of parses that extend from the Galactic Center, first seen in 1984. Even larger bubbles rise above these , as seen by MeerKAT, have been observed in the γ-ray portion of the spectrum and could be of similar origin.
MeerKAT's 4.4 billion rand ($ 330 million) is an array of 64 radioactive dishes, 13.5 meters each, on a remote site in the North Cape Province. It will form the heart of the South African part of the SKA, which should be built in the 2020s. The second section of the observatory will be in Australia.
This article has been reproduced with permission and was first published on September 11, 2019