Astronomers using powerful telescopes to observe nearby galaxies have discovered one of the largest black hole jets ever recorded. The jet, spanning a million light-years in size, is not only huge, it is also estimated to be 50 times larger than the Milky Way. Nearby galaxy NGC 2663 lies just 93 million light-years away. Similar black hole jets have been spotted earlier, but the enormous size of the newly discovered jet and its close proximity to the Milky Way make it a unique discovery.
Astronomers at Western Sydney University observed it using ordinary telescopes and saw the elliptical shape of a typical elliptical galaxy. However, they found something extraordinary when they looked at the Milky Way using a super telescope called the Australian Square Kilometre Array Pathfinder (ASKAP) operated by the Commonwealth Scientific and Industrial Research Organisation (CSIRO).
By analyzing the radio waves recorded by the telescope, astronomers have discovered a jet of material ejecting the Milky Way from a central black hole. It was found to be 50 times larger than the Milky Way and, if visible to the naked eye, would appear larger than the moon in the night sky. In the Evolution of the Universe Map (EMU) survey, astronomers noted that galaxies are pushed back on either side of the jet. Found this to be similar to the effect in a jet.
As the exhaust plume passes through the atmosphere, ambient pressure pushes it from side to side. This, in turn, causes the jet to expand and contract, causing it to pulsate as it travels. The pulsations manifest as regular bright spots that astronomers call “shock diamonds.”
Such impact diamonds have been spotted earlier in smaller galaxy-sized jets, but this is the first time astronomers have observed the jets contracting massively from the side.