A radio wave map of the Milky Way's turbulent centre, created using the MeerKAT telescope. A new study has used radio observations to reveal previously undetected 'tornado'-like structures at the heart of our galaxy. (Image credit: I. Heywood, SARAO)
New telescopic observations with unprecedented detail have revealed that “cosmic tornadoes” are swirling around the supermassive black hole at the center of the Milky Way.
Astronomers' recent efforts have zoomed in on the cosmic vortices using the Atacama Large Millimeter/submillimeter Array (ALMA) in Chile. Although these rotating features have been spotted before, the new ALMA data is 100 times sharper than previous observations, the team reported in a new paper published in the journal Astronomy & Astrophysics.
The researchers began by pointing ALMA at a region of the galaxy known as the central molecular zone (CMZ), which surrounds our galaxy’s core and is home to swirling clouds of dust and gas. The team wanted to find out what mechanism drives the constant motion of these clouds.
They used ALMA to study certain molecular compounds — such as silicon oxide, which is particularly effective at detecting shock waves — inside the vortex. This allowed the team to reveal previously unnoticed features in cosmic dust storms, including a new type of long, thin filament that appears to form as shock waves pass by.
“Unlike any other object we know of, these filaments really surprised us” because they appear to be moving quickly and in the opposite direction to the surrounding structures, said Kai Yang, an astronomer at Shanghai Jiaotong University and lead author of the study.
A radio map of the central Milky Way obtained with the MeerKAT telescope, with previously unknown filamentary structures observed with the ALMA telescope marked as red rectangles.
The researchers describe these filaments as cosmic tornadoes. “They are turbulent streams of gas, dissipate rapidly, and effectively distribute materials into the environment,” the authors noted. The team’s observations suggest that, in addition to releasing silica, these vortices can disperse complex organic molecules such as methanol, methyl cyanide, and cyanoacetylene throughout the CMZ and beyond.
“ALMA's high angular resolution and exceptional sensitivity were key in detecting these molecular emission lines associated with the thin filaments and in confirming that there are no interstellar interactions between these structures.
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