A A 3D model of a black hole’s disordered feeding system Reveals a possible explanation for the strange behavior of dim-switched quasars.
It’s very unusual for galaxies to do anything in a hurry, but 'changing appearance’ quasars are an exception.
They can change Radiation jet Just inside on and off years Or even months. This vanishing activity shocked astrophysicists when they first saw it 2014and continues to mystify scientists.
sitting in The center of the baby constellations, quasars (or 'quasi-stellar radio sources’) typically burn about 27 trillion times brighter than our Sun. Quasars are composed of a supermassive black hole and its food: gas and dust swirling around it.
Past models assumed that matter orbiting a black hole would relatively cross the event horizon. in an orderly manner, like water going down a drain. It was considered a slow process 10,000 years or more.
„For decades, people made the huge assumption that accretion disks are aligned with the rotation of the black hole.” He says Lead author Nick Gass is an astrophysicist at Northwestern University in the US.
„But the gas feeding these black holes doesn’t know which way the black hole is spinning, so why would they automatically align? Changing the alignment changes the picture drastically.”
When the team created a 3D computer model of a rotating black hole that was not aligned with its accretion disk, strange things began to happen.
Instead of behaving like a pizza base being spun around a chef’s finger, the accretion disc began to deform and tear.
It was broken into an inner sub-disc and an outer disc, and each disc rotated at a different angle like a gyroscope.
This disc splitting was caused by the spinning black hole twisting the spacetime around it – a general-relativistic process Frame-dragging.
„When [black holes] Spin, they pull the space around them like a giant carousel, forcing it to spin as well. He says Cheese
Frame-tracking has a strong drag on matter orbiting closer to the black hole and a weaker drag on matter orbiting further out.
This difference causes the inner disc to spin faster than the outer disc.
First, friction and pressure hold the disk together. But eventually, the black hole’s warping of space-time causes the inner disk to break up into a single disk that is smaller and easier to move around.
„The place where a black hole wins is the place it tears.” He says Cheese
These two discs hit each other at different angles, causing a shock. 'Streamers’ from external disk It rained In the inner sub-disc, it forces matter to accelerate into the black hole.
This extra mass drives the inner disk toward the black hole. These processes may shed light on why quasars can suddenly turn on and off.
„Classical accretion disk theory cannot explain this drastic variation,” He says Cheese
„But the phenomena we see in our simulations could explain this. The rapid brightening and dimming corresponds to the destruction of the inner parts of the disk.”
This article has been published The Astrophysical Journal.
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