Astronomers reveal supermassive black hole's intense magnetic field

Astronomers reveal supermassive black hole's intense magnetic field
This artist's impression shows the surroundings of a supermassive black hole, typical of that found at the heart of many galaxies. The black hole itself is surrounded by a brilliant accretion disc of very hot, infalling material and, further out, a dusty torus. There are also often high-speed jets of material ejected at the black hole's poles that can extend huge distances into space. Credit: ESO/L. Calçada

Astronomers from Chalmers University of Technology have used the giant telescope Alma to reveal an extremely powerful magnetic field very close to a supermassive black hole in a distant galaxy. The results appear in the 17 April 2015 issue of the journal Science.

A team of five astronomers from Chalmers University of Technology have revealed an extremely powerful magnetic field, beyond anything previously detected in the core of a galaxy, very close to the event horizon of a supermassive black hole. This new observation helps astronomers to understand the structure and formation of these massive inhabitants of the centres of galaxies, and the twin high-speed jets of plasma they frequently eject from their poles.

Up to now only weak magnetic fields far from black holes—several light-years away—had been probed. In this study, however, astronomers from Chalmers University of Technology and Onsala Space Observatory in Sweden have now used Alma to detect signals directly related to a strong magnetic field very close to the event horizon of the supermassive black hole in a named PKS 1830-211. This magnetic field is located precisely at the place where matter is suddenly boosted away from the black hole in the form of a jet.

The team measured the strength of the magnetic field by studying the way in which light was polarised, as it moved away from the black hole.

"Polarisation is an important property of light and is much used in daily life, for example in sun glasses or 3D glasses at the cinema," says Ivan Marti-Vidal, lead author of this work.

"When produced naturally, can be used to measure magnetic fields, since light changes its polarisation when it travels through a magnetised medium. In this case, the light that we detected with Alma had been travelling through material very close to the black hole, a place full of highly magnetised plasma."

The astronomers applied a new analysis technique that they had developed to the Alma data and found that the direction of polarisation of the radiation coming from the centre of PKS 1830-211 had rotated.

Magnetic fields introduce Faraday rotation, which makes the polarisation rotate in different ways at different wavelengths. The way in which this rotation depends on the wavelength tells us about the magnetic field in the region.

The Alma observations were at an effective wavelength of about 0.3 millimetres, the shortest wavelengths ever used in this kind of study. This allows the regions very close to the central black hole to be probed. Earlier investigations were at much longer radio wavelengths. Only light of millimetre wavelengths can escape from the region very close to the black hole; longer wavelength radiation is absorbed.

"We have found clear signals of polarisation rotation that are hundreds of times higher than the highest ever found in the Universe," says Sebastien Muller, co-author of the paper. "Our discovery is a giant leap in terms of observing frequency, thanks to the use of Alma, and in terms of distance to the black hole where the has been probed—of the order of only a few light-days from the . These results, and future studies, will help us understand what is really going on in the immediate vicinity of supermassive ."


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ALMA probes mysteries of jets from giant black holes

More information: Science on 17 April 2015, vol 348, issue 6232 www.sciencemag.org/lookup/doi/ … 1126/science.aaa1784
Journal information: Science

Citation: Astronomers reveal supermassive black hole's intense magnetic field (2015, April 16) retrieved 21 October 2019 from https://phys.org/news/2015-04-astronomers-reveal-supermassive-black-hole.html
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Apr 16, 2015
"This magnetic field is located precisely at the place where matter is suddenly boosted away from the black hole in the form of a jet"

Therefore, particle acceleration via gravitational attraction forming an accretion disk which propels the material on the edge of the 'event horizon' is not needed. The Lorentz force is all that is required. Same goes for the corona, solar wind, cometary tails, etc.

Apr 16, 2015
An article about "Black holes" that actually didn't make me laugh at it in ridicule. Nothing but real physics at work here both in the observation and the method of interpretation.

These results, and future studies, will help us understand what is really going on in the immediate vicinity of supermassive black holes.


Damn right

Except for the fact that BH's are nothing but fairy tales. What they are looking at is a plasmoid, complete with the expected particle beams and strong magnetic fields.

http://focusfusio...id_image

Apr 16, 2015
Magnetism may even warp space and time. Not wormholes.

Apr 17, 2015
Just as predicted. Nice piece of research. Now we can do the same thing for a million galaxies and look a few light days away from the event horizons of a million supermassive black holes.

Get ready for an avalanche of data about the magnetic fields created by the accretion disks of black holes.

Apr 17, 2015
Actually they didn't measure the magnetic field, only its integral over a light path and they estimated the magnetic field to be at least tens of Gauss, or much greater.

Apr 17, 2015
So the authors are just beginners and real experts are the crackpots reacting on this blog.

Didn't you know? 'Real' experts don't need to do any actual work. That's beneath them. They just need to produce word salad on public science journalsim site comment section (because there they are sure they won't be noticed/taken apart by real scientists)...and can pretend that their three brain cells actually line up.

It'd be funny if it weren't so sad to watch.

Apr 17, 2015
@antialias_physorg

So the authors are just beginners and real experts are the crackpots reacting on this blog.

Didn't you know? 'Real' experts don't need to do any actual work. That's beneath them. They just need to produce word salad on public science journalsim site comment section (because there they are sure they won't be noticed/taken apart by real scientists)...and can pretend that their three brain cells actually line up.

It'd be funny if it weren't so sad to watch.


^^^^

I just cackled out loud when I read this

Im still LOLing

okay okay okay Im done

Yeah that was definitely funny...

Apr 17, 2015
DaSchneib had to begin his post with "exactly as predicted" as though nobody knew where the jets where originating from and were only working off a mathematical theory.

The more intense laughter ensued when, just for shits and giggles I read the abstract linked to this article in which, after mentioning accretion disks, they still freely admit to not knowing precisely how the jets are accelerated.


Reset, this is the guy's greatest forte......he looks at other posts by those with a demonstrable scientific background, then he follows up paraphrasing their posts deleting just enough words to make it read like he thought of the correct answer all by himself. I asked him once if he could solve a Differential Equation, his response was that he wasn't here to talk about his math background, but rather to discuss the subject at hand, he ducked that one as deftly as he could, but not untypical for someone who has never seen the inside of a college physics classroom.


Apr 17, 2015
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Apr 17, 2015
How the magnetic field is supposed to penetrate the event horizon?

Because there is no event horizon.

Apr 17, 2015
docile, the magnetic field doesn't penetrate the EH. The magnetic field is close to the EH, but not inside it.

After observing these threads for a while, I've decided that the majority of nay-sayers are religious people dogmatically defending their faith, and others gain their knowledge from sources closely linked to the Ancient Aliens TV show.

"It ain't what you don't know that'll hurt ya. It's what you know that ain't so"

Apr 17, 2015
docile, the magnetic field doesn't penetrate the EH. The magnetic field is close to the EH, but not inside it


You should have explained why the magnetic field doesn't penetrate the EH.........it's because magnetic fields are photons & not only is a visible light photon unable to reach escape velocity at that point, the same goes for the entire electro-magnetic spectrum.


Apr 17, 2015
Basic logic says to me that once matter gets far enough into the accretion disk that the matter is broken down to atom level that there should be an extremely powerful electric current flowing in a circle there. Just like a coil. A black hole with any accretion disk should act like a really big bar magnet on galactic scale. Without a disk the field should collapse until the black hole gets fed again.

Apr 17, 2015
docile, the magnetic field doesn't penetrate the EH. The magnetic field is close to the EH, but not inside it.
The no hair theorem says black holes have exactly three characteristics visible from outside the event horizon:

* mass
* electric charge
* angular momentum

It's been suggested that magnetic charge is a fourth, but not proven rigorously. And, of course, magnetism is merely the relativistic correction for the finite speed of propagation of the electric field, which is one of the three. Magnetism is currently a "hot" field of investigation in physics, and I expect this conjecture will be proven or disproven in the next decade or so, given advances in supercomputing.

Apr 17, 2015
Actually they didn't measure the magnetic field, only its integral over a light path and they estimated the magnetic field to be at least tens of Gauss, or much greater.
That's a pretty potent magnetic field, considering the Earth's magnetic field is 0.65 Gauss or less, and the Sun's is only about 1 or 2 Gauss.

Apr 17, 2015
How the magnetic field is supposed to penetrate the event horizon?
Magnetism is just the relativistic correction for the fact that electric charge propagates at the speed of light, not at infinite speed.

Black holes can have electric charge. See the no hair theorem. This implies that they can have a net magnetic field, due to the propagation delay of their electric charge.

Apr 17, 2015
RBL first originally and correctly proposed the strongest magnetic fields in the universe near black holes. See page 37 of "A Theory of the Relativistic Spinrevorbital" [ http://www.academ...AB049585 ] click 'Full Text PDF' for a free download of the manuscript. Now a group of scientists at Chalmer in Sweden confirms by observation this prediction as published in Science Mag this week!

Apr 18, 2015
This comment has been removed by a moderator.

Apr 18, 2015
This comment has been removed by a moderator.

Apr 19, 2015
many jets points to magnetic monopole character of black holes..


OK, so you want to be the other resident nuclear physicist. I'd like for you to explain to this Electrical/Nuclear Engineer how you make a "monopole magnet"? If you can bring one into our lab for examination, I can almost guarantee you our company will pay you hundreds of millions of dollars for a lifetime of royalties for that magnet. No, you can't just point to a BH or some miniscule transient magnetic domain inside somebody's collider lasting for a nano-sec, I mean something we can draw up plans for & put on a production line.

Apr 20, 2015
It's been suggested that magnetic charge is a fourth, but not proven rigorously
We already have an observational evidence, that the magnetic field of black holes gets separated from their angular momentum in similar way, like inside of pulsars under situation, when black hole jets aren't perpendicular to galactic plane.
Ummm, that's a nice picture but it doesn't prove the magnetic field isn't generated by the accretion disk.

In addition the asymmetric character of many jets points to magnetic monopole character of black holes..
ummwut

Apr 20, 2015
These comments make me sad. you all miss the implications of this work, but given the level of knowledge displayed, other than the obvious there are other questions raised here. Just a clue ask yourself why the magnetic field exists beyond the EV and very annoyingly as usual time seems to stand still or oh yea no it didn't.
NB. before you reply, yes I did read all of the above.

Apr 21, 2015
STRJ, it's cranky to claim all the scientists are wrong.

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