Black holes traditionally spin in the same direction as their surrounding debris discs, all the while emitting a powerful jet of radiation that anchors their home galaxy. But some black holes spin in the opposite direction of their surrounding debris. reports on a new study that shows these strange black holes create more powerful jets of radiation. 

The development of stars is often dependent on the jet radiation coming from the supermassive black holes at the center of their galaxies. Some feel this study could change how scientists understand the evolution of galaxies. As explains, prograde black holes spin in the same direction as the disks. Retrograde black holes spin against the flow. Scientists have long thought that the faster the black hole spins, the more powerful the jet of radiation. This was called the “spin paradigm” model. 

However, there were problems with this traditional paradigm. Experts found that some prograde black holes didn’t emit jet radiation. 

Understanding this jet radiation is of utmost importance to astronomers. Rita Sambruna is a researcher at NASA Goddard Space Flight Center and worked on this new study about retrograde black holes. As she told, "Jets transport huge amounts of energy to the outskirts of galaxies, displace large volumes of the intergalactic gas, and act as feedback agents between the galaxy's very center and the large-scale environment … Understanding their origin is of paramount interest in modern astrophysics.”

These more powerful jets may have something to do with the Reynold's conjecture, named after the theoretical astrophysicist Chris Reynolds of the University of Maryland in College Park. Apparently, in backward-moving black holes, there is more space between the black hole and the inner edge of its orbiting disk. This creates more room for the build-up of magnetic fields — which scientists say powers the jets. This new research also shows that the supermassive black holes evolve over time from a retrograde to a prograde state. 

David Meier is a theoretical astrophysicist at JPL. As he told, this new information solves the issue of the spin paradigm as well. According to Meier, "Everything now fits nicely into place."

For further reading:

Backward-moving black holes are more powerful
New research: Black holes that spin in the opposite direction emit stronger jets of radiation.