Mark Megahan
If you look at a two dimensional image of a black hole “top down,” in the moments just before it flares, you’ll notice some interesting things. Hot plasma spirals like a whirlpool into the gravity well of the black hole as expected. Things get really freaky at the outside edge of the “event horizon” point of no return. That’s where the flow reverses and launches some material outward. Fast. This “accelerated material generates the flare” and now we know how the magnetic field accomplishes it’s magic.
Flares powered by magnetic reconnection
Any piece of matter flung out in one of the flickering flares at the edge of a black hole is truly lucky to even exist. A nothingth of an inch closer to the supermassive singularity and it would have been sucked right out of the universe entirely.
Instead, “snapping” lines of magnetic force fling the material spaceward in glowing streaks of plasma.
Over at the Flatiron Institute, a team of researchers figured out that “breaking and reconnecting magnetic field lines near the event horizon release energy from a black hole’s magnetic field, accelerating particles that generate intense flares.” Insiders note their “findings hint at exciting new possibilities.”
Astronomers have always been a little touchy about having to explain why black holes aren’t really black. The intense light shows dancing just outside the event horizon of supermassive black holes, including the one at our galaxy’s core, is as beautiful as it is inexplicable. Until now.
Using some of the most powerful computers ever built they solved the puzzle. “Energy released near a black hole’s event horizon during the reconnection of magnetic field lines powers the flares.”
Field lines are a whole lot harder to snap than one of those rubber bands in the kitchen drawer. That means the recoil is a whole lot harder.
Slingshot hot plasma
The new high definition simulation models indicate “that interactions between the magnetic field and material falling into the black hole’s maw cause the field to compress, flatten, break and reconnect.” What that means to astronomers is the “process ultimately uses magnetic energy to slingshot hot plasma particles at near light speed into the black hole or out into space.”
The outward bound ones “directly radiate away some of their kinetic energy as photons and give nearby photons an energy boost. Those energetic photons make up the mysterious black hole flares.”
Their model clearly shows “the disk of previously infalling material is ejected during flares, clearing the area around the event horizon.”
The stellar housecleaning not only neatens up the area it “could provide astronomers an unhindered view of the usually obscured processes happening just outside the event horizon.”
“The fundamental process of reconnecting magnetic field lines near the event horizon can tap the magnetic energy of the black hole’s magnetosphere to power rapid and bright flares,” study co-lead author Bart Ripperda explains. “This is really where we’re connecting plasma physics with astrophysics.”
To come up with the spectacular results, Ripperda and his colleagues “used computing time on three supercomputers — the Summit supercomputer at Oak Ridge National Laboratory in Tennessee, the Longhorn supercomputer at the University of Texas at Austin, and the Flatiron Institute’s Popeye supercomputer located at the University of California, San Diego.” Even with “deep thought” at their disposal, “the project took millions of computing hours.” It was worth it. “The result of all this computational muscle was by far the highest-resolution simulation of a black hole’s surroundings ever made, with over 1,000 times the resolution of previous efforts.“
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