A giant cosmic funnel sucks in gas from its surroundings. But not all of that gas falls in — some is spat back out, like splashes from boiling water. That's exactly what the ultraluminous X-ray source NGC 5204 X-1 does: a compact object (likely a black hole) feeds so voraciously that the excess escapes in powerful jets.

Using the RGS spectrometer on XMM-Newton, astronomers split the source's X-ray light into its component colors, much as a prism breaks up sunlight. In the spectrum, they spotted lines from gas moving both toward us and away from us. This tells us the outflow takes the shape of two cones spreading in opposite directions, like twin lighthouse beams.

Beyond the fast jets, the team also examined slower gas. From oxygen lines, they pinned down its density: roughly 10 billion particles per cubic centimeter (by comparison, Earth's atmosphere at the surface has about a million times more). The temperature of this gas is at least 150,000 degrees. It turns out that both particle collisions and radiation from the black hole itself influence the gas's ionization — a 'hybrid' regime that hasn't always been taken into account before.