Galactic apocalypse: This composite image of the galaxy 3C321 shows the jet from a black hole at the centre of the larger galaxy (lower left, purple), striking the edge of a companion galaxy to the upper right, the first time such an interaction has been found. The bright blue spot (and cloud) indicates where the jet has struck the smaller galaxy and energy has been dissipated.

Credit: X-ray: NASA/CXC/ CfA/D Evans et al.; Optical/UV: NASA/ STScI; Radio: NSF/VLA/CfA/D Evans et al., STFC/JBO/MERLIN

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SYDNEY: Space telescopes have spotted a powerful jet from a supermassive black hole blasting a nearby galaxy with radiation. Never seen before, this galactic violence may have a profound effect on any planets in the jet's path and also trigger bursts of star formation in its destructive wake.

"We've seen many jets produced by black holes, but this is the first time we've seen one punch into another galaxy like we're seeing here," said Dan Evans, who led the team behind the discovery at the Harvard-Smithsonian Centre for Astrophysics in Massachusetts, USA. "This jet could be causing all sorts of problems for the smaller galaxy it is pummelling."

Supermassive black holes

Known as 3C321, the galactic system contains two galaxies in orbit around each other. The U.S. space agency NASA's Chandra X-ray Observatory has shown that both galaxies contain supermassive black holes at their cores, but the larger galaxy has a jet emanating from its black hole. The smaller galaxy appears to have drifted into the path of this jet.

This "death star" galaxy, as NASA has dubbed it, was discovered through the combined efforts of both space and ground-based telescopes, including the Hubble Space Telescope, and The Very Large Array telescope in New Mexico, USA. The find will be detailed in an upcoming edition of The Astrophysical Journal.

Jets from supermassive black holes produce high amounts of radiation, especially high-energy X-rays and gamma rays. The combined effects of this radiation and particles travelling at almost the speed of light could severely damage the atmospheres of any planets lying in the path of the jet. For example, protective layers of ozone in the upper atmosphere would be destroyed.

Star-former

These jets transport enormous amounts of energy far from black holes and enable them to affect space across vast areas, so learning more about them is a key goal for astrophysicists.

"We see jets all over the universe, but we're still struggling to understand some of their basic properties," said study co-author Martin Hardcastle of the University of Hertfordshire in England. "This system of 3C321 gives us a chance to learn how they're affected when they slam into something like a galaxy and what they do after that."

The effect of the jet on the companion galaxy is likely to be substantial said NASA, because the galaxies in 3C321 are extremely close at a distance of only about 20,000 light years apart. They lie approximately the same distance as Earth is from the centre of the Milky Way galaxy.

The experts predict that the massive influx of energy and radiation from the jet could induce the formation of large numbers of stars and planets after its initial wake of destruction is complete.