Black Hole Particle Jets Explained

Screaming Cactus writes "A team of researchers led by Boston University's Alan Marscher have apparently worked out the physics behind the particle streams emanating from many black holes. According to the researchers, 'twisted, coiled magnetic fields are propelling the material outward.' By watching an 'unprecedented view' of a black hole in the process of expelling mass, they were able to confirm their theory, predicting where and when bursts of energy would be detected."

Re:Hawking Radiation

[PhuCknuT]

Yes, this is completely different, but it's not exactly the black hole emitting anything. The jets are from material that hasn't fallen into the black hole yet, being accelerated along the axis of rotation by the twisted magnetic fields outside the black hole.

Re:Hawking Radiation

[ekstrom]

This is radiation from the accretion disk, which both supplies the material and twists up the fields which then accelerate the material. It's not from the hole itself. Of course it is all powered by the hole's gravitational field.

Re:Hawking Radiation

[Jugalator]

These particle jets aren't emitted from the actual "depths" of a black hole, but as the article says, ejected due to twisted magnetic fields perpendicular to its accretion disk. Once you get closer, space bends even the magnetic fields inwards, and everything else. And what goes that far is later emitted as Hawking radiation, the only form of energy theorized to be emitted from a black hole, in time believed to "evaporate" the black hole itself.

Re:This is how science works

[Kenja]

Well, except global warming, obviously. That just gets accepted as is, since anyone who suggests otherwise is probably an oil company shill.

Um, we have decades of direct testing and thousands of years of indirect data supporting global warming. It has been and continues be heavily tested.

Re:The scatological aspects of astronomy.

[oodaloop]

Ok, so its juvenile and stupid.

Not really. You may not be aware, but one of the reasons the term Black Hole stuck around was to annoy French astrophysicists (the term translates to a bodily orafice in French). The question was later posed (by Wheeler, I believe) as to whether black holes have 'hair', meaning do they give off observable radiation or other phenomena, much to the chagrin of his French counterparts. The question was posed, FWIU, mostly just so American physicists could snicker while French physicists had to talk about black holes and hair in public conferences. And it turns out that yes, black holes do in fact have hair.

Now we have black holes expelling mass. I'm sure you're not the only one finding this humorous.

Re:Hawking Radiation

[evanbd]

Well, large black holes don't evaporate -- even the cosmic background radiation is enough to add more mass than they lose to Hawking radiation. The CMB is at ~2.7K, and a 1 solar mass black hole has a temperature of 60nK from the Hawking radiation.

Re:The scatological aspects of astronomy.

[The Only Druid]

Didn't he say that matter could NOT escape a black hole?

This isn't matter escaping a black hole. This is matter, outside the black hole, being accelerated and hurtled outwards by the forces of the black hole.

Old hat

[jessica_alba]

From http://en.wikipedia.org/wiki/Birkeland_current [wikipedia.org] "A Birkeland current generally refers to any electric current in a space plasma, but more specifically when charged particles in the current follow magnetic field lines (hence, Birkeland currents are also known as field-aligned currents). They are caused by the movement of a plasma perpendicular to a magnetic field. Birkeland currents often show filamentary, or twisted "rope-like" magnetic structure."

I wonder when they will discover that these "super massive destructive forces" are actually electric powerhouses that light up the cosmos.

Re:This is how science works

[93 Escort Wagon]

You're making the very common mistake of using sloppy terminology. "Global warming" is not necessarily the same thing as "anthropogenic (human-caused) global warming". The former is directly observable; the latter is not. We can build computer models that predict how human activity causes (or at least contributes to) the warming; and, if warming continues over time, the chance that it is just due to natural variation goes down with every new year the trend holds. But just observing that the climate has warmed, in and of itself, is not proof that it's been induced by human activity.

Re:Hawking Radiation

[PhuCknuT]

It's both, they radiate very slow and the CMB will be warmer than them for a long time. I just looked it up, a stellar mass black hole will take 10^67 years to evaporate. I was way off when I said trillions. :)

The cool thing is, as they get smaller, they radiate faster. So they get smaller and hotter exponentially, and finally die (in theory...) in a massive burst of gamma rays. In the last second, they emit as much energy as a 5000000 megaton nuke. Would be a hell of a show (from a safe distance).

Re:Does it even matter?

[evanbd]

There's a black hole. Quantum vacuum fluctuations create a particle-antiparticle pair near it, both with positive mass. One falls in, the other escapes. Thanks to quantum weirdnesses, the mass for the escaping one gets stolen from the black hole. Half the time it will be the antiparticle escaping, and half the time the particle. (Overall, though, they'll mostly do the same thing and both fall toward it or away from it, and annihilate each other with no net effect. But on the rare occasion when they get created in the right spot with the right energy, one will fall in and the other will escape.)

Of course, you could just read the Wikipedia article [wikipedia.org].

Re:Hawking Radiation

[qeveren]

If you have a spherical collection of particles randomly orbiting an object, collisions between particles tend to average out their angular momentum, eventually concentrating them into a thin disk. The oblateness of the rotating primary about which they orbit tends to force that ring into alignment with the primary's equator.

I am french that is not informative

[aepervius]

Black hole translate to "trou noir", which is as funny (or unfunny) as "black hole" is in english. I don't ever recall an astrophysicists in France which was annoyed, or amused. I would REALLY like to see a reference to this.And to the moderator, such an assertion would require at least a lnik or reference to be modded informative +5. Right now at best it is only +5 funny.