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A Black Hole’s Afterburn

By Stephen Luntz

A Black Hole’s Afterburn

The full text of this article can be purchased from Informit.

Rather than one smooth path, images taken from the Australia Telescope Compact Array reveal a sequence of bright dots along the jet known as PKS 0637-752. Although PKS 0637-752 has been known for some time, and studied in depth by the Chandra X-Ray Telescope, it has never been imaged with such clarity before.

“Massive jets like this one have been studied for decades, since the beginning of radio astronomy, but we still don’t understand exactly how they are produced or what they’re made of,” says Dr Leith Godfrey of the Curtin University node of the International Centre for Radio Astronomy Research.

“One intriguing possibility is that the pattern we see in this cosmic jet is produced in the same way as the pattern in the exhaust from fighter jet engines,” Godfrey adds. “If the brighter patches are caused by the same process in astronomical jets as they are in earthly jet engines, then the distance between them can give us important information about the power of the jet and the density of the surrounding space.”

These patches, known as mots, are commonly seen in quasar jets but Godfrey says: “The interesting thing is that these are quite regularly spaced, and there are lots of them, making this a really striking example. We can use the observational clue as a constraint on the source dynamics.”

Mots appear in any supersonic jet. “Hot gas comes...

The full text of this article can be purchased from Informit.

The glowing trail of material extending out from a super­massive black hole resembles the afterburn of a fighter jet, Australian astronomers have noted. However, in this case the trail is two million light years long, the distance from here to the Andromeda Galaxy.