Tour: PJ352-15

Astronomers may have found an extraordinarily long jet from a supermassive black hole in the early Universe using NASA's Chandra X-ray Observatory. This would be an important discovery if scientists can confirm this result with future observations. This jet is coming from a rapidly growing black hole about 12.7 billion light years from Earth, or, in other words, less than a billion years after the Big Bang. This would make it the most distant black hole with a jet detected in X-rays.

The implications of this black hole's distance go beyond just superlatives. One of the key questions in astronomy today is how did supermassive black holes — that is, those with millions or even billions times the mass of the Sun — form in the very early Universe?

Despite their powerful gravity and fearsome reputation, black holes do not inevitably pull in everything that approaches close to them all at once. Material orbiting around a black hole in a disk needs to lose speed and energy before it can fall farther inwards to cross the so-called event horizon, the point of no return. Moreover, there are limits to how much material a black hole can ingest at once, which means it can take a very long time for a black hole to consume enough material to accumulate millions of solar masses. That is, unless something intervenes to speed up that process.

The jet that the Chandra data uncovered in X-rays may be just what this black hole needed in order to grow so quickly. A jet of particles could help the black hole grow by decreasing the speed and energy of surrounding material, allowing it to fall inwards and cross the event horizon more rapidly.

The length of the jet is also an important clue in this study. The Chandra data indicates that the jet extends some 160,000 light years. This gives astronomers a timeline to determine just how long the black hole has been adding bulk during this growth spurt.

X-ray studies like this are particularly important because as electrons in the jet fly away from the black hole at close to the speed of light, they move through and collide with photons making up radiation left over from the Big Bang, and boosts the energy of the photons up into the X-ray range that Chandra can detect. This quasar and its jet demonstrate that X-ray astronomy is crucial for learning about the very early Universe and its black holes.