Tuesday , June 15 2021

New simulations provide clues on how to escape from a black hole



How to escape from a black hole

This visualization of a general relativistic simulation of uncolysis plasma shows the density of the positrons near the horizon of the event of a rotating black hole. Plasma instabilities create island-like structures in the field of intense electric current. (Credit: Kyle Parfrey et al. / Berkeley Lab)

Black holes are known for their insatiable appetites, confronting matter with such ferocity that even light can not escape after being swallowed.

Less well understood, however, is how black holes purify their energy in rotation by placing plasma near light in space to the opposite sides of one of the most powerful displays in the universe. These jets can stretch out for millions of light-years.

New simulations conducted by researchers working at the Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley combine decades of old theories to provide a new insight into the drives in the plasma jets that allow them to steal energy from the black holes. gravitational fields and move it away from their gaping mouth.

Simulations can provide a useful comparison for high-resolution observations from the Event Horizon telescope, an array that is designed to provide the first direct images of the regions where the plasma jets are formed.

The telescope will allow for new views of the Black hole in the center of our own Milky Way Galaxy, as well as detailed views of other super massive black holes.

"How can energy be extracted in the black hole rotation to make jets?" Said Kyle Parfrey, who led the simulation work while he was a postdoctoral student from Einstein's Department of Nuclear Sciences at the Berkeley Laboratory. – It's been a matter of a long time.


This simulation shows a rotating black hole (bottom) and an insensitive plasma jet (top). The simulation shows the density of the electrons and the positrons and the magnetic field lines. The "epoch" of the black hole, in which all the particles have to rotate in the same direction as the hole, is shown in green. (Credit: Kyle Parfrey et al. / Berkeley Lab)

He is now a senior research fellow at NASA's Goddard Space Center in Maryland, Parfrey is the lead author of a study published on January 23 in Physical Review Letters, which explores the simulations in detail.

Simulations for the first time combine a theory that explains how electric currents around a black hole convert magnetic fields into forming jets, as a separate theory explains how particles can flow through a black hole point without return – the horizon of events. a distant observer to transfer negative energy and reduce the total energy of rotation of the black hole.

It's like eating a snack that makes you lose calories instead of acquiring them. The black hole actually loses the mass as a result of flooding these particles with "negative energy".

Computer simulations have difficulty in modeling all complex physics involved in the release of plasma jets, which need to take into account the creation of pairs of electrons and positrons, the particle acceleration mechanism and the emission of light into the jets.

Berkeley Lab has contributed significantly to plasma simulations over its long history. Plasma is a gaseous mixture of charged particles, which is the most common state of matter.

Parry said she realized that more complex simulations for better description of jets would require a combination of experience in plasma physics and the general theory of relativity.

"I thought it was time to try and get these two things together," he said.

Running at NASA's supercomputer center, Ames Research Center, in Mountain View, California, simulations include new numerical techniques that provide the first unconventional plasma model where collisions between charged particles do not play an important role – in a severe gravitational field associated with a black hole.

Simulations naturally produce effects known as the Blandford-Znajek mechanism, which describes twisted magnetic fields that form jets, and a separate Penrose process that describes what happens when negative energy particles are swallowed by the black hole.

The Penrose process, "although it does not necessarily have to contribute so much to extracting the energy of black hole rotation," says Parfrey, "is probably directly linked to the electric currents that distort the magnetic fields of the jets."

Although more detailed than some earlier models, Parfrey notes that his team simulations are still coping with the observations and are somehow idealized to simplify the calculations needed to perform the simulations.

The team intends to better model the process by which electron-positron pairs are created in jets to investigate the plasma distribution of jets and their radiation emissions more realistic than the observations. They also plan to expand the scope of simulations to include the flow of seizure around the horizon of black hole events known as its accretion stream.

"We hope to provide a more consistent picture of the whole issue," he said.

Other participants in the study are Alexander Filipov, who is Einstein's post-graduate student at the University of California at Berkeley, and Benoit Cerruti, CNRS researcher at the University of Grenoble Alpes, France. Parfrey and Philipov were members of the Center for Astronomy and Theoretical Astrophysics at the University of California at Berkeley, and Philipov was already at the Flatiron Institute in New York.

The work is backed by NASA through the Einstein Postgraduate Scholarship Program, CNES, Labex [email protected], The NASA High-Tech Computing Program, TGCC, CINES, and the Simons Foundation.

Publication: Kyle Parfrey, et al., & Quot; First Principles of Black Simple Shoot Plasma Simulations & quot ;, Physical Review Letters, 2018; Дой: 10.1103 / PhysRevLett.122.035101


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