Black Hole IGR J17091-3624: Stellar-Mass Black Hole Winds Moving Nearly 20 Million MPH

A group of scientists have clocked the winds of a stellar-mass black hole at 20 million MPH, nearly 10 times faster than what is normally associated with this class of black hole.

Stellar-mass black holes are created by the collapse of pretty huge stars and typically weigh between five and ten times the mass of our sun. But supermassive holes are millions or billions of times bigger.

“It’s a surprise this small black hole is able to muster the wind speeds we typically only see in the giant black holes,” said co-author Jon M. Miller of the University of Michigan. “In other words, this black hole is performing well above its weight class.”

Using NASA’s Chandra X-ray Observatory, astronomers observed winds blowing from the gases surrounding the stellar-mass black hole (named IGR J17091). According to Space.com, these winds are generated by the magnetic field of black holes, which interact with the high-temperature ions to cause rapid movements. Those movements either take the form of winds or jets.

In the latter, the ionic gasses fire in a focused stream in a direction perpendicular to the accretion disk surrounding a black hole.

“This is like the cosmic equivalent of winds from a category five hurricane,” said Ashley King, lead author of the study, also from the University of Michigan.

So why does all this matter?

Observing the unusually fierce wind patterns around this particular black hole has given astronomers a better understanding of how black holes operate in general.

One unanticipated finding was that the winds are carrying as much matter away from the hole as is being gathered by its insurmountable gravity.

“Contrary to the popular perception of black holes pulling in all of the material that gets close, we estimate up to 95 percent of the matter in the disk around [the black hole] is expelled by the wind,” King said.

The black hole IGR J17091-3624 research and observations from Chandra and the National Radio Astronomy Observatory’s Expanded Very Large Array was published in the 20 February issue of The Astrophysical Journal Letters.

via Space.com
Image: Harvard