Ghost hunting isn’t typically the sort of thing you’d expect the Chandra space telescope to be doing. Evidently though, it’s rather good at it! Specifically an x-ray ghost betraying the presence of a galaxy’s supermassive black hole. Feel free to go away and make up your own jokes about “spectral lines”…
When astronomers talk about ghosts, what they’re really talking about are images which show you an event that has passed. Neighbouring gas clouds can often show residual heating or light echoes long after the event which caused them has ended – hence, you’re witnessing the ghost of an event.
So this blue blobby looking thing (shown as part of a composite image), is an x-ray ghost. A diffuse x-ray source left behind by a black hole outburst in the early Universe, just 3 billion years after the Big Bang. The supermassive black hole which created this eruption really put out an immense amount of power. And I really do mean immense. Inspite of the numerous times in the past I’ve talked about incredible temperatures and immense amounts of power – I read this, blinked, and had to read it again…
This supermassive black hole erupted with the power of a billion supernovae. Just try and think about that for a moment. A billion times the (already difficult to imagine) power behind a supernova. Actually, don’t think about that for too long. It’s enough to give you nightmares.
It was that prodigous eruption which caused the diffuse x-ray ghosts spied by Chandra. Mind you, no one’s explicitly said what precisely this “ghost” is. I’d speculate that the x-rays are coming from superheated gas clouds. They certainly look like they could have been heated by a black hole’s polar jets. But then, I’m no expert on this.
The most exciting part of a discovery like this is what we could learn from it. There’s really an awful lot we don’t understand about how the Universe worked back then. In particular, the way galaxies grow and evolve is becoming quite a bone of contention for the astronomical community at large. Seeing something like this is quite firm evidence of a supermassive black hole feeding and growing. What precisely we’ll find out remains to be seen, but for now at least we’re a step closer to understanding more about how the Universe worked 10 billion years ago.
Top: X-ray (NASA/CXC/IoA/A.Fabian et al.), Optical (SDSS), Radio (STFC/JBO/MERLIN)
Bottom: Cartoon Network/Adult Swim