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Friday, June 19, 2020

A University of Iowa astrophysicist is part of an international team that has observed a black hole hurling hot material into space at close to the speed of light.

The flare-up between the black hole and a companion star make up a system called MAXI J1820+070, located in the Milky Way galaxy, about 10,000 light years from Earth. The scientists working with NASA’s Chandra X-ray Observatory found that while some of the hot gas from the companion star will cross the "event horizon" (the point of no return) and fall into the black hole, some of it is blasted away from the black hole in a pair of short beams of material, or jets. These jets are pointed in opposite directions, launched from outside the event horizon along magnetic field lines.

Philip Kaaret, professor in the Department of Physics and Astronomy at Iowa, wrote the software used to analyze the images obtained with the Chandra X-ray Observatory to measure how the black hole jets move. He also assisted in the scientific interpretation and writing the paper.

“The result of the paper is that the jets carry more energy than is radiated in X-rays,” Kaaret says. “This means that most of the energy liberated by matter falling in towards the black hole actually goes into powering the jets that flow out from the accretion disk.”

The black hole's behavior is based on four observations obtained with Chandra in November 2018 and February, May, and June of 2019. The findings are reported in a paper published in The Astrophysical Journal Letters.