The process by which stars and planets are born may also be the driver for the formation and expansion of black holes. This has come from studies of supermassive black holes from Northwestern University.
A supermassive black hole weigh as much as millions or billions of stars, yet how these phenomena grow to these sizes has been a mystery. Now, new observational evidence that magnetized, rotating winds feed black holes may provide the answer for what helps them grow so large.
The findings have come from the study of the galaxy ESO320-G030. This points to extremely powerful rotating, magnetic winds helping this galaxy’s central supermassive black hole to grow.
ESO320-G030 is located just 120 million light years from Earth, making it suitable for study using telescopes at the Atacama Large Millimeter/submillimeter Array (ALMA) Observatory in Chile.
“It is well-established that stars in the first stages of their evolution grow with the help of rotating winds – accelerated by magnetic fields, just like the wind in this galaxy,” explains lead researcher Mark Gorski.
He adds: “Our observations show that supermassive black holes and tiny stars can grow by similar processes, but on very different scales.”
The researcher measured light from molecules carried by winds from the galaxy’s core, tracing how the winds are launched by a growing — or soon to be growing — supermassive black hole. By using ALMA, we were able to study light from behind thick layers of dust and gas.
Specifically, the scientists studied light from hydrogen cyanide molecules. Using Doppler effect technology, the researchers imaged fine details and trace movements in the gas, which revealed patterns suggesting the presence of a magnetized, rotating wind. This showed how the newly discovered wind adds another process, which feeds the black hole and helps it grow.
As matter approaches the black hole, it first collects in a chaotic, spinning disk. There, magnetic fields develop and grow stronger. The magnetic fields help lift matter away from the galaxy, creating a vortex of wind. As matter is lost to the wind, the spinning disk slows, which turns the slow trickle of matter into a stream — meaning that matter flows more easily into the black hole.
Following this discover, the scientists intend to study the centres of other galaxies, searching for hidden spiralling outflows.
The research appears in the journal Astronomy & Astrophysics. The paper is titled “A spectacular galactic scale magnetohydrodynamic powered wind in ESO 320-G030.”
