A rainbow being sucked into a black hole9/12/2023 ![]() ![]() Ghez (UCLA) for her 2020 Physics Nobel Prize award, along with colleague Renhard Genzel (UBC). Ghez become 1 of 4 women recognized with the physics Nobel Prize. As a woman science communicator, I am thrilled to see Dr. Ghez for her incredible work and her well-deserved Nobel Prize in Physics. I am so humbled (and psyched!)… I can now say that I’ve created black hole art for a Nobel Prize winner! But really, I’m not here to boast, I’m here to congratulate Dr. When it’s near the edge, the light we see shifts to green, then red. We are now organising to put programmes in place for future events, as the detailed physics of how black holes suck in matter is still very poorly understood.Black Hole Art Celebrating Andrea Ghez’s Nobel Prize A view of the blue star as it travels around the black hole at different time points. But it demonstrates the importance of reacting quickly to these events with our most powerful telescopes in order to catch these events. These observations are just a small part of the huge dataset collected worldwide during the outburst, and much more remains to be done as it is all thoroughly digested. This phenomenon also helps us to estimate how much mass was ejected through the wind. Once the outburst had finished, we were able to detect a nebula – a cloud of dust and gases – formed from material expelled by the wind. It may sound counter-intuitive, but we have known for many years that, in spite of the intense gravitational field close to the Event Horizon of the black hole (within which nothing can escape), the enormous pressure of radiation itself, combined with the spin and magnetic field of the black hole, can lead to large fractions of the infalling matter being spat out – often at velocities approaching the speed of light. If this material had not been “blown away”, it is likely that the outburst would have lasted much longer. This is linked to how and at what rate black holes accrete material, and grow in size (mass) – important parameters for understanding the evolution of black holes on all scales in the universe. The finding allows us to explain why the outburst was so brief, lasting only two weeks, compared to the previous outburst which lasted three months and helped us discover the object in the first place. And while radio jets accelerated by processes around the black hole itself have been seen in these X-ray outbursts before (including V404 Cyg), this was the first time we had seen a strong wind blown off the outer accretion disc.Īrtist’s impression of the black hole emitting wind. It is thanks to the high resolution provided by the CANARIAS telescope’s huge aperture that we were able to link this wind with the X-ray flare. ![]() The wind is likely driven by the X-rays created in the outburst heating the disc surface to high enough temperatures to escape the disc’s gravity and flow outwards. Formed in the outer layers of the accretion disc, this wind has to move quickly to be able to escape from the immense gravitational field surrounding the black hole. They show a powerful wind of hydrogen and helium emanating from the black hole and travelling at a mind-boggling speed of 3,000 kilometres a second. The results, which have just been published in Nature, are surprising. This causes the matter to reach very high velocities and temperatures, emitting huge quantities of X-rays in the process, at which point they are spotted by orbiting X-ray satellites. They happen when so much material is accumulated in the accretion disc that it becomes unstable and the disc suddenly starts dumping matter onto the black hole. X-ray outbursts from black holes are rare (V404 Cygni is one of the best known), typically happening on timescales of decades. What makes V404 Cygni special is that, at only 8,000 light years away, it is one of the closest known black holes to the Earth, and has a particularly large accretion disc (with a radius of about 10m kilometres), which makes its outbursts extremely bright. The outer regions of the disc, however, emit visible light, which means we can observe this region from the ground. Its hotter, innermost zones emit X-rays, which we cannot detect from the Earth’s surface, as they are absorbed by our atmosphere, and hence must be studied from space. The matter falling towards the black hole forms a so-called accretion disc. During this process it continuously swallows material from the star. The black hole is part of a binary system – it has a low-mass companion star (only about half the mass of our sun) that orbits around the black hole every 6.5 days.
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