I thought that only hawking radiation could escape a black hole. Now a paper describing a vast jet of emitted plasma??
The article doesn't quite clarify this point. It mentions the jets shooting from below and above the black holes, but does this mean they're emerging from their interior or being created by the accretion of superheated material that forms in orbit around black holes?
The article simple states this, which seems wrong given the immense gravity of black holes:
>When supermassive black holes become active—in other words, when their immense forces of gravity tug on and heat up surrounding material—they are thought to either emit energy in the form of radiation or jets.
So the holes themselves emit energy jets or their accretion disks do? Sloppy damn phrasing and reporting, and all too common for science subjects.
Its not coming out of the black hole itself, its more like the black hole has an accretion disk around it of material that is being sucked in. The dynamics of the huge forces and energies involved can cause jets to form, throwing high energy particles away from the black hole. The jets still represent a tiny fraction of the matter, most of which is still heading into the hole.
Hawking radiation is one process, but for spinning black holes, especially ones with accretion disks and magnetic fields around them, there are two more theoretical predictions: the Blandford–Znajek process and the Penrose process.
> I thought that only hawking radiation could escape a black hole.
I think this is likely a misconception too. Hawking radiation does not come from inside a black hole, it comes from the event horizon. A virtual particle/anti-particle pair is created close enough to the event horizon that one of them falls in and the other escapes. This means the origin is outside the hole!
Similar story with jets. They're created by the interactions of matter as it falls towards the black hole (gaining energy), but before it actually falls inside.
You may have heard that a black hole is the most efficient way to convert matter to energy apart from antimatter annihilation. This is that.
In the accretion disk, friction and collision between fragments, molecules, atoms cause things to reach incredible temperatures. The matter gets so incredibly hot that the radiation it emits is actually enough to offset the black hole's gravity and prevents more matter falling in faster. The innermost section of the disk is so ludicrously hot that matter dissociates into subatomic particles and becomes a plasma. This plasma is very energetic and moves very fast and creates a very strong magnetic field. This interacts with the electric field produced by the black hole. This plus the stupendous distortion of spacetime caused by the black hole's rotation causes the magnetic fields to twist up tightly in a vortex about the axis of rotation.
Again, the energies involved are impossibly huge. We're converting matter into energy at something like 95% efficiency. Just through gravity!
Because the plasma is so highly charged, the magnetic vortices are so powerful, and the twist is so tight, it essentially creates a particle accelerator on a galactic scale. Plasma from the accretion disk is sucked into the vortex by the insane magnetic fields. Particles spin round and round in the vortex until they get as close to light speed as is possible. The vortex also confines the jet into a cone, blasting out charged particles with impossible velocities along the axis of rotation.
These jets convert matter into pretty much every kind of energy. Radiation across the entire spectrum, lightspeed particles, magnetic and electric fields. It's really impossible to overstate just how much energy these things throw out. It's just a few degrees shy of a sustained matter/antimatter reaction on stellar scales running for millenia.
These things can extinguish entire galaxies. Not sterilize, extinguish. They can blast away any free gas in a galaxy, immediately and irrevocably halting star and planet formation. Not even just in the host galaxy. Exceptionally powerful quasars can extinguish galaxies lightyears away.
And again, this is only driven by gravity. Nothing else. All of the impossibly huge energies are produced by nothing more than matter falling into a gravity well.
The article doesn't quite clarify this point. It mentions the jets shooting from below and above the black holes, but does this mean they're emerging from their interior or being created by the accretion of superheated material that forms in orbit around black holes?
The article simple states this, which seems wrong given the immense gravity of black holes:
>When supermassive black holes become active—in other words, when their immense forces of gravity tug on and heat up surrounding material—they are thought to either emit energy in the form of radiation or jets.
So the holes themselves emit energy jets or their accretion disks do? Sloppy damn phrasing and reporting, and all too common for science subjects.