The findings continue to unfold in the middle of the Milky Way.
Colosal bubbles originated in this area, emitting radio waves that were detected with the aid of a new telescope. The structures are a sign of a prolonged eruption of activity from the region around the now relatively dormant supermassive black hole in the center of the galaxy, researchers reported on September 12 Nature .
An image of the ethereal bubbles shows the capabilities of the South Africa Radio Astronomy Observatory of the MeerKAT radio telescope, a set of 64 dishes spread over an area eight kilometers across Carnarvon. The completed telescope begins to collect data in spring 2018.
These radio wave-emitting bubbles extend hundreds of light-years above and below the Milky Way plane. And they point to "something extraordinary happened at the galactic center," says astrophysicist Ian Heywood of the University of Oxford.
Heywood and colleagues estimated that an event involving a large amount of energy – equivalent to an explosion of approximately 100 stars – sent the matter out of the region around the black hole of some million years ago. Fast, electrically charged particles produced at that event, accelerated by the magnetic field, created radio waves of bubbles, the team suggests.
A temporary black hole that fed the frost for a long time could have spawned the bubbles, as the behemoth gulped down matter and spewed the excess. Or the bubbles could be the result of a mob of stars forming around the black hole. Those stars could explode into supernovas, and drive their hearts out.
Bubbles are bright on their sides, suggesting that a shock wave of material was plowing out, researchers found. This means that whatever makes the bubbles is not an ongoing process, but one that opens after a calm.
These radio bubbles are "a piece of mosaic" in the center of space, said astrophysicist Jun-Hui Zhao of the Harvard-Smithsonian Center for Astrophysics in Cambridge, Mass., Who was not involved in the discovery. In March, astronomers reported X-ray chimneys emanating from the heart of space ( SN: 3/20/19 ). These chimneys are covered with new spotted radio structures, suggesting a common source. And earlier observations revealed massive gamma-ray bubbles, much larger than X-ray and radio structures, ballooning from both sides of the galaxy ( SN: 11/9/10 ).
Observing new pieces of mosaics, such as radio bubbles, can help scientists determine the origin of some of the previously uncovered strangles. For example, bubbles cover a set of mysterious structures known as radio filaments, tall, thin strips discovered in the 1980s. Although it is not yet clear how the filaments form, the new result links them to radio bubbles.
"This is actually the first time you see a clear connection between the flow and illumination of these filaments," said astronomer Daniel Wang of the University of Massachusetts Amherst who was not involved in the research. "It's an amazing image."