From the mouth of the supermassive black hole at the center of galaxy M87, two giant jets stream thousands of light-years into space. Scientists still don’t fully understand the physics behind jets, which are made up of a mixture of electrically charged particles, or plasma (SN: 3/24/21) but they are “really, really surprising,” says astrophysicist Alejandro Cruz-Osorio of the Goethe University Frankfurt. So he and his colleagues created a computer simulation of M87’s black hole and the swirling gas that surrounds it in an accretion disk. Objective: find out what this black hole is already famous for – a photo in 2019 (SN: 4/10/19) – became such a jet-setter.
Under the right conditions, that simulation produces jets that match M87’s observations, researchers report Nov. nature astronomy, The black hole spins spiraling magnetic fields that surround two high-energy beams of electrons and other charged particles. The results suggest that the black hole must be spinning faster, at more than half its maximum speed allowed by the laws of physics, and possibly up to 94 percent of its maximum possible speed.
It proved important to get the energy of the jet’s electrons right. When the magnetic fields in the jet rearrange in a process known as magnetic reconnection (SN: 8/3/21), the electrons are accelerated, resulting in a lot of energy in more of them. This effect was not included in earlier simulations, but it was important for the simulated jets to act like their real-world counterparts.
