Black hole jets ‘dance’ in the wind from a massive companion star |
Black holes are among the most extreme objects in the universe. They can fling material outwards at speeds close to that of light, in powerful beams of plasma known as jets. These jets are thought to be among the most energetic phenomena in the cosmos.
Our new work, published today in Nature Astronomy, challenges this intuition. We find that something as seemingly ordinary as the “wind” from a star can rival – and even shape – the behaviour of these powerful jets.
The Cygnus X-1 system is a cosmic waltz between a black hole and a massive star.
The black hole is the first ever discovered. It weighs about 21 times the mass of our Sun, compressed into a region roughly 100 kilometres across. It’s in what’s known as a binary system with a much larger companion star that’s almost 40 times as massive as the Sun. The black hole and the star whirl around each other in their orbit once every 5.6 days.
For about 20,000 years, the black hole has been feeding on material from this star. It does so by capturing the star’s powerful stellar wind, using its intense gravitational........