compile/linda
Astronomers have discovered hundreds of mysterious cosmic threads pointing to the supermassive black hole at the center of our galaxy. Each of these strange threads extends 5 to 10 light years in space, forming “points” and “lines”, like the Morse code in the universe.
Northwestern University astronomer Farhad Yusef-Zadeh said he was “shocked” by the filamentary structure in data collected by the MeerKAT radio telescope in South Africa’s Northern Cape province. They spread out from the center of the Milky Way, 25,000 light-years from Earth, like splintered spokes on a gigantic wheel.
MeerKAT, the most sensitive radio telescope in the world, captured these images of the filaments during a 200-hour scanning observation of the Milky Way’s core. “They seem to be traceable to the black hole (at the center of the galaxy) and they tell us a story about that black hole,” Zade told the Guardian.
Forty years ago, Zade discovered some longer filaments surrounding the Sagittarius A* black hole (SgrA*) at the center of the Milky Way, after analyzing data collected by the Very Large Array telescope in New Mexico. And perpendicular to the plane of the Milky Way’s disk, it is 150 light-years long.
What creates the numerous vertical filaments is unclear, but the study found that they possess powerful magnetic fields and emit radio waves as they accelerate particles in cosmic rays to nearly the speed of light.
Zade says researchers, including himself, have been so busy studying the properties of this giant vertical filament that they have barely noticed the presence of some of the shorter horizontal filaments at the center of the Milky Way.
“Previous research focused on how to understand the vertical filaments, and somehow the horizontal structure was ignored,” Zade said. He was amazed to suddenly discover these new structures pointing in the direction of the black hole, which would not have been discovered had it not been for the MeerKAT telescope.
When the scientists removed the background from the MeerKAT image and filtered out the noise, the shorter horizontal filaments that spread out from the center of the Milky Way came into focus. Zade said that his research team recently published a paper in “The Astrophysical Journal Letters” (The Astrophysical Journal Letters), describing the new filament structure, the formation process is different from the previous larger vertical filaments.
He suspects that an ejection of material from the black hole about 6 million years ago hit surrounding stars and gas clouds, creating streaks of hot plasma pointing toward the black hole. The effect is similar to blowing a few drops of oil paint across a canvas with a hair dryer.
“A black hole’s eruption interacts with the objects it encounters and distorts its shape, blowing everything in the same direction.”
By studying cosmic filaments, astronomers hope to learn more about the spin of the Milky Way’s central black hole and the accretion disk of matter that orbits it and falls into it. “The Milky Way has a lot of structures that we can’t explain, and there’s still a lot to explore,” Zade said.
