A visualization from a supercomputer simulation shows how positrons behave in the vicinity of the event horizon of a spinning black hole.
Credit: Kyle Parfrey et al / Berkeley Lab
The attraction of a black hole is so strong that nothing, even light, can escape if it gets too close. However, there is a way to escape a black hole ̵
Because black holes devour the matter in their environment, they also spew out strong rays of hot plasma with electrons and positrons. the antimatter equivalent of electrons. Just before the lucky incoming particles reach the event horizon or point without return, they begin to accelerate. Almost at the speed of light, these particles move away from the horizon of the event and are thrown outwards along the axis of rotation of the black hole.
These huge and powerful streams of particles, known as relativistic jets, radiate light that lets us see telescopes. Although astronomers have been observing the jets for decades, no one knows exactly how the exiting particles get all that energy. In a new study, researchers at the Lawrence Berkeley National Laboratory (LBNL) in California have re-examined the process. [The Strangest Black Holes in the Universe]
"How can the energy in the rotation of a black hole be extracted to produce rays?" Kyle Parfrey, who led the black hole simulation during his postdoctoral studies at the Berkeley Lab, said in a statement. "That has been a question for a long time." Parfrey is now Senior Fellow at NASA's Goddard Space Flight Center in Maryland.
Parfrey and his team developed to answer this question a set of "supercomputer simulations" that combined "decades of theories to gain new insights into the driving mechanisms in the plasma jets that allow them to steal energy from the strong gravitational fields of the black holes and away from their gaping mouths "In other words, they investigated how the extreme gravitational force of a black hole can give the particles so much energy that they begin to radiate.
" For the first time, the simulations unite one Theory Explaining How Electric Currents Rotate Around a Black Hole "Magnetic Fields in Forming Jets," with a Separate Theory Explaining How to Particle By Dur We will cross the point of a black hole with no return – the event horizon – to give a distant observer the appearance of transporting negative energy and lowering the rotational energy of the black hole, "LBNL said. "It's like eating a snack that causes you to lose calories instead of winning them, and the black hole actually loses mass when you sip in those" negative energy "particles."
Parfrey said that he combined the two theories in a combined attempt to merge ordinary plasma physics with Einstein's general theory of relativity. The simulations not only had to address the acceleration of the particles and the light coming from the relativistic jets, but also consider the way in which the positrons and electrons are formed in the first place: through the collisions of high-energy photons. like gamma rays. This process, called pair production, can turn light into matter.
"The results of the new simulations are not radically different from those of the old … simulations, which is reassuring in a sense." Robert Penna, a researcher at the Columbia University Center for Theoretical Astrophysics, who was not involved in the study, wrote in a related article on "Positions" in the journal Physical Review Letters.
"Parfrey et al., However, reveal interesting and new behavior," Penna said. "For example, they find a large population of particles whose relativistic energies are negative, as measured by an observer far from the black hole, and when these particles fall into the black hole, the total energy of the black hole decreases."
There was a surprise. Parfrey's simulations show that so many of these negative-energy particles are flowing into the black hole, "that the energy they gain by falling into the hole is comparable to the energy gained from winding the magnetic field," he said Penna. "Reworking is required to confirm this prediction, but if the effect of negative-energy particles is as strong as claimed, expectations for the radiation spectra of black hole jets may change."
Parfrey and his team plan to do this Improve their models by comparing the simulations with observation data from observatories such as the new Event Horizon Telescope, designed to capture the first photos of a black hole. "They also plan to expand the scope of the simulations to take into account the flow of the accidental material around the black hole event horizon, the so-called accretion flux," LBNL officials said.
"We hope to have a more unified picture of the whole problem," said Parfrey.
The study was published on Wednesday (January 23) in Physical Review Letters.