Jet streams emanating or pulsing outward from stellar objects are often the result of rotational forces. Spinning has long been the explanation for the jets of black holes.

But astronomers at the Harvard-Smithsonian Center for Astrophysics have spotted two non-spinning black holes in the galaxy M82 with similarly powerful jets, suggesting rotation is not the prerequisite scientists thought it was.

The discovery highlights a larger truth about black holes. The holes themselves are rather simple -- defined by their mass, spin and electric charge -- while their surrounding architecture and cosmic accouterments are less well understood.

Rotation-powered jets are spawned by a black hole's accretion disk, the ring of condensed material that forms as gas and debris is pulled in from the surrounding space. As the accretion disk spins with the black hole, ionized particles are flung outward -- sometimes at close to the speed of light. In addition to rotational forces, the power of localized magnetic fields are also involved in fueling the jets.

But in a new paper, published in the Monthly Notices of the Royal Astronomical Society, astronomers suggest jets can also be powered by the intense radiation of hot gas.

As radiation is pulled in by a black hole's gravity and packed into the accretion disk, it can under some circumstances become so pressurized that jet particles are driven outward at nearly half the speed of light. The discovery may explain the phenomenon of narrow ultraluminous X-ray beams scientist have observed near black holes of roughly ten solar-masses in size.