Mysterious magnetar boasts one of strongest magnetic fields in Universe

Aug 14, 2013
Magnetic star reveals its hidden power
Artist's impression of a magnetar Credit: ESA/ATG Medialab

(Phys.org) —A team of astronomers including two researchers from UCL's Mullard Space Science Laboratory has made the first ever measurement of the magnetic field at a specific spot on the surface of a magnetar. Magnetars are a type of neutron star, the dense and compact core of a giant star which has blasted away its outer layers in a supernova explosion.

Magnetars have among the strongest magnetic fields in the Universe. Until now, only their large scale magnetic field had been measured. However, using a new technique and observations of a magnetar in X-rays, the astronomers have now revealed a strong, localised surface magnetic field on one.

Magnetars are very puzzling . Astronomers discovered them through their unusual behaviour when observed in X-ray wavelengths, including sudden outbursts of radiation and occasional giant flares. These peculiar features of magnetars are caused by the evolution, dissipation and decay of their super-strong magnetic fields, which are hundreds or thousands of times more intense than those of the more common type of neutron stars, the radio pulsars.

The magnetic field of a magnetar can have a complex structure. The most obvious, and easy-to-measure, component is the large scale , which is shaped (and behaves) much like a regular bar magnet's. This is known as the dipolar field.

The study was carried out on a magnetar called SGR 0418+5729. A few years ago, this star was discovered to have a relatively gentle dipolar magnetic field compared to other magnetars. However, the star was showing the typical flaring and bursting activities seen in other magnetars, leading scientists to suggest that the star's might be caused by a field hidden beneath its surface.

Magnetic star reveals its hidden power
Sometimes, the surface breaks and the hidden magnetic field leaks out (artist's impression) Credit: ESA/ATG Medialab

This new study, based on observations from ESA's XMM-Newton X-ray , has finally found evidence that SGR 0418+5729 is indeed concealing a very strong magnetic field in its interior.

"This magnetar has a strong magnetic field inside it, but it is hidden beneath the surface. The only way you can detect that is to find a flaw on the surface, where the concealed magnetic field can leak out," says Silvia Zane (UCL Mullard Space Science Laboratory), one of the co-authors of the study.

Such magnetic leaks would also explain the outbursts and flares of radiation observed from magnetars. The warped magnetic field trapped inside the star builds up stress below the magnetar's surface, occasionally breaking its 'crust' apart and releasing sudden flashes of X-rays.

Magnetars are far too small – only around 20km across – and distant for even the best telescopes to see any details on their surfaces. They appear just as dots of light in astronomers' observations. So the team had to look for indirect signs of variation on SGR 0418+5729's surface. To do this, they measured how the magnetar's X-ray emissions varied as the star rotates.

"SGR 0418+5729 rotates once every 9 seconds. We found that at one point during the rotation, the magnetar's X-ray brightness drops sharply. That means something on or near one part of the surface is absorbing the radiation," adds Roberto Turolla (an honorary professor at MSSL and co-author of the study).

Magnetic star reveals its hidden power
Closeup of the magnetic field leaking out of a magnetar (artist's impression) Credit: ESA/ATG Medialab

The team believes that a concentration of protons over a small area of the magentar's surface – perhaps as little as a few hundred metres across – is absorbing the X-rays. The protons are confined to a small volume near the surface by a strong, localised magnetic field emerging from the 's interior, giving powerful evidence that a strong and twisted internal magnetic field lurks beneath the surface.

"This exciting discovery also confirms that, in principle, other pulsars with relatively low external magnetic fields might conceal a similar strong magnetic field in the interior. As a result, many pulsars may switch on and become active flaring magnetars for a while, so in the future we may discover much more magnetars than what we previously thought. This call for a major revision of our current ideas of formation and amplification in neutron stars," explains Zane.

The study is published in the journal Nature.

Explore further: Can astronomy explain the biblical Star of Bethlehem?

More information: "A variable absorption feature in the X-ray spectrum of a magnetar," by A. Tiengo et al is published in Nature, 15 August 2013.

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cantdrive85
1 / 5 (20) Aug 14, 2013
I'm definitely far stupider after reading this drivel, but as some here say "it sells".
cantdrive85
1 / 5 (16) Aug 14, 2013
This call for a major revision of our current ideas of magnetic field formation and amplification in neutron stars," explains Zane.

To say the least!
DonGateley
3 / 5 (2) Aug 14, 2013
How could surface protons avoid being pulled into the neutron soup?
Q-Star
4.2 / 5 (5) Aug 14, 2013
How could surface protons avoid being pulled into the neutron soup?



Protons are lighter than neutrons. The neutrons are as close together as physically possible,,, the only thing stopping them from further collapsing into a black hole is the particle (neutron) degeneracy pressure.
thermodynamics
4.2 / 5 (10) Aug 14, 2013
I'm definitely far stupider after reading this drivel, but as some here say "it sells".


I don't believe that for a second.

Your concepts of an electric universe just can't get any "stupider". Can you please explain to us how a pulsar really works in your universe? I need some amusement.
cantdrive85
1.2 / 5 (22) Aug 14, 2013
Step right up folks, get your neutron stars over heeere! (old tyme salesman voice)
They've got your neutrons, they've got your protons, and they even have their frozen-in fields!
What more can you ask for, folks? The gravity cure-all for the ages.
Get your neutron stars over heeere!
kim1
5 / 5 (7) Aug 14, 2013
I find it amazing that people can ridicule the theories of these creative scientist without any analysis or even conjecture of their own. Leads my to believe people think science is a religion.
cantdrive85
1 / 5 (20) Aug 14, 2013
I find it amazing that people can ridicule the theories of these creative scientist without any analysis

The analysis was given by the scientist; "This call for a major revision of our current ideas of magnetic field formation and amplification in neutron stars," explains Zane."
even conjecture of their own

It's not my own, but there is definitely conjecture;
http://www.thunde...sars.htm

Leads my to believe people think science is a religion.

And yes, the big bang and relativity are religions.

"Religion is about turning untested belief into unshakable truth through the power of institutions and the passage of time."
Richard Dawkins

It's the essence of the BB and modern astrophysics.
barakn
3.7 / 5 (9) Aug 15, 2013
Once again, the treasure trove of information at http://www.thunde...sars.htm staggers the imagination.
cantdrive85
1 / 5 (16) Aug 15, 2013
A coherent, complete cosmology will be a trove of information, with a lot less "This call for a major revision of our current ideas".
DonGateley
3.2 / 5 (14) Aug 15, 2013
Is there any field besides physics that brings such large numbers of uneducated, yet certain, fools to the discussion?
DonGateley
3 / 5 (4) Aug 15, 2013
How could surface protons avoid being pulled into the neutron soup?



Protons are lighter than neutrons. The neutrons are as close together as physically possible,,, the only thing stopping them from further collapsing into a black hole is the particle (neutron) degeneracy pressure.


Yes, but a proton will join with a free electron and become squeezed to a neutron (give or take some energy) won't it? Is there something preventing those protons from attracting any electrons floating about? I'm unable to see what would keep such an object from remaining neutral.
thermodynamics
3.4 / 5 (5) Aug 15, 2013
Don asked: "Yes, but a proton will join with a free electron and become squeezed to a neutron (give or take some energy) won't it? Is there something preventing those protons from attracting any electrons floating about? I'm unable to see what would keep such an object from remaining neutral."

I had the same conceptual problem until I found out that the pressure at the surface of the neutron star can be low enough for free protons and below the threshold to crush electrons into them to form the neutrons. However, remember how dense the neutron material is. It is not just the gravitational pull, but also the mass of neutron soup as you go down into the star. For instance, if you think about it, going to the center of a neutron star or any other massive object means gravitational force goes to zero (at the center of a homogenous sphere). However, the pressure of the column of neutrons is huge. It is the pressure below the surface that makes the neutrons. (continued)
antialias_physorg
4 / 5 (4) Aug 15, 2013
Is there something preventing those protons from attracting any electrons floating about?

There's some intense heat/radiation about (way more than you'd need to ionize an electron away from a proton)
thermodynamics
3.7 / 5 (3) Aug 15, 2013
Continued for Don: If you think about the pressure going up as it would in a liquid, you can see that as you dive deeper into the ocean the pressure becomes high enough to crush a submarine. Think about diving into neutron soup. The pressure goes up very quickly and it can be much lower at the surface. Don't get me wrong, the gravitational force is much higher on the surface than it would be for a normal star because the mass is concentrated in a very small diameter sphere. However, the pressure goes up very quickly as you go into the sphere. Naturally, this is all dependent on the mass of the object and the diameter. Also, you have to use general relativity for a dense object like that because Newtonian gravity will not give you the right answers.
Greenwood
5 / 5 (8) Aug 15, 2013
It's not my own, but there is definitely conjecture; http://www.thunde...sars.htm


Except simply saying "circuits" is a) untestable as it isn't even a model and b) doesn't explain simple observations like pulsars in binary systems. Not to mention recycling, spin-down, accretion, x-ray emission, the incredible brightness temperatures and emission mechanisms. All it does so is state that there can be electrical circuits that run at 1000-0.1 Hz, as if anyone doubted that. It does nothing to explain the other observations of pulsars.
Shabs42
5 / 5 (4) Aug 15, 2013
Is there any field besides physics that brings such large numbers of uneducated, yet certain, fools to the discussion?


Religion? Evolution? Politics? Just name a topic, really. Or go to any internet site about any topic that has comments enabled.
antialias_physorg
5 / 5 (7) Aug 15, 2013
Is there any field besides physics that brings such large numbers of uneducated, yet certain, fools to the discussion?

Religion? Evolution? Politics? Just name a topic, really.

Problem is more the converse: Not that there are more fools in science dabtes, but that debates on science also draws a few educated people - so the fools tend to be pointed out more easily.

(And there's hardly a field where you can make a fool of yourself as objectively as in science debates. So if people are out to know once and for all whether they truly are fools they've certainly come to the right place)
brt
4 / 5 (8) Aug 15, 2013
Is there any field besides physics that brings such large numbers of uneducated, yet certain, fools to the discussion?

Religion? Evolution? Politics? Just name a topic, really.

Problem is more the converse: Not that there are more fools in science dabtes, but that debates on science also draws a few educated people - so the fools tend to be pointed out more easily.

(And there's hardly a field where you can make a fool of yourself as objectively as in science debates. So if people are out to know once and for all whether they truly are fools they've certainly come to the right place)


their sole reason for commenting here is because they hate science, period. You see it on all websites; a person seeks out a topic they don't like so that they can argue about it despite their complete ignorance; example: cantdrive85. Nobody else gives a shit about their argument, but they just want to keep on arguing despite the complete lack of interest from others.
cantdrive85
1 / 5 (13) Aug 15, 2013
Is there any field besides physics that brings such large numbers of uneducated, yet certain, fools to the discussion?

I don't know, just look here at all the fools, scientists included, postulating about this mathematical construct. Makes no difference neutron stars can't be tested or falsified, yet are so sure they no only exist, but their pseudoscientific viewpoints. I'm not anti-science, I'm anti, anti-science, as such I berate the pseudo scientists and their devoted followers.
brt
4 / 5 (8) Aug 15, 2013
Is there any field besides physics that brings such large numbers of uneducated, yet certain, fools to the discussion?

I don't know, just look here at all the fools, scientists included, postulating about this mathematical construct. Makes no difference neutron stars can't be tested or falsified, yet are so sure they no only exist, but their pseudoscientific viewpoints. I'm not anti-science, I'm anti, anti-science, as such I berate the pseudo scientists and their devoted followers.


Seen here, the internet troll commonly insists on instigating arguments and having the last word, even if the last word is completely absent of meaning. The goal of the internet troll is to drive the conversation away from the topic and onto a childish back and forth absent of purpose; the only environment internet trolls can thrive in...lets watch.
cantdrive85
1 / 5 (15) Aug 15, 2013
Except simply saying "circuits"

Wrong on a), b), and c). It's completely possible to test, unlike the standard theory. And they aren't just "simply saying circuits", the star is a plasma focus, it's emissions are a reflection of the fluctuating current powering it. The x-rays certainly pose no problem, nor does the binary, brightness, or the temps/emissions.
What's truly unbelievable, the idea that these massive mathematical constructs can spin faster than a dentists drill and not fly apart, hence the need to add so much mass to the "model". But I guess since a scientist proposed it I should cast aside all reason in favor of his mathematical constructs. Or not!
cantdrive85
1.3 / 5 (15) Aug 15, 2013
"We are having wool pulled over our eyes if we let ourselves be convinced that scientists, taken as a group, are anything special in the way of brains. They are very ordinary professional men, and all they know is their own trade, just like all other professional men. There are some geniuses among them, just as there are mental giants in any other field of endeavor."
— Anthony Standen

There seem to be a LOT of sheep around here!
brt
4 / 5 (8) Aug 15, 2013
"We are having wool pulled over our eyes if we let ourselves be convinced that scientists, taken as a group, are anything special in the way of brains. They are very ordinary professional men, and all they know is their own trade, just like all other professional men. There are some geniuses among them, just as there are mental giants in any other field of endeavor."
— Anthony Standen

There seem to be a LOT of sheep around here!


fascinating...
Greenwood
5 / 5 (6) Aug 15, 2013
The x-rays certainly pose no problem, nor does the binary, brightness, or the temps/emissions.


Tell me where can I find the evidence that this is the case because you have given nothing? All the thunderboltz article says is it's a circuit. Simply claiming it can explain everything with absolutely zero evidence provided is nothing short of blind faith. I brought up observations, you dismissed them without a shred of evidence and have the cheek to call other people sheep.

You apparently don't know anything about radio astronomy either it's brightness temperature, not brightness and temperature. And yes the colossal brightness temperatures are an enormous problem, you need a model of emission mechanisms to say you can explain that.
cantdrive85
1 / 5 (14) Aug 15, 2013
This article suggests such a consideration. The current just happens to be pointed at us, which enables the observation.
http://www.nrao.e...agnetar/

Tell me where can I find the evidence

It's one article, are you suggesting I should somehow be able to deduce the entire standard theory from reading this one specific article? You along with most others here are content to read one article, and if that one article doesn't satisfy every question you have you dismiss it. This is a ridiculous notion, the current understanding of "neutron stars" has been developed over time, the notion the EU should have a complete and neatly prepackaged explanation for every aspect that is observed is asinine. Just as you learn this "theory", over time with an understanding of the fundamentals, so too is it necessary to have at least a basic understanding of the entire theory to make an informed opinion.
http://www.thunde...ontents/
cantdrive85
1 / 5 (12) Aug 15, 2013
you need a model of emission mechanisms to say you can explain that.

Here's a start, but to be sure the specific output will reflect the conditions and chemical make-up present in a specific locale, although the arrangement of the materials should be predictable.
http://scholar.go...as_vis=1

GSwift7
3 / 5 (2) Aug 15, 2013
Eh, don't get too excited about the speculative interpretation of the data just yet.

All they really know is that the xray source brightens and dims with a regular frequency. They "interpret" this to represent a surface feature and rotation. Then they further interpret this surface feature to be protons blocking the xray source. Then they further interpret the protons to be the result of an magnetic anomaly poking through the bulk magnetic field. Then they interpret that to indicate strong magnetic fields inside the weaker outer field.

This is all based on observations of one single magnetar.

This is published in Nature, so assume it passed peer review, but that doesn't mean there weren't peer reviewer comments suggesting alternate explanations or even revisions. You could see other papers with interpretations that do not require "a major revision of our current ideas". Any time I see that phrase, especially with a small sample size, I'm skeptical.
cantdrive85
1 / 5 (15) Aug 15, 2013
They "interpret" this to represent a surface feature and rotation.


Much of cosmology is about "interpretation". The only evidence of black holes is how astrophysicists interpret the observations. that's why Alfven stated;
"Students using astrophysical textbooks remain essentially ignorant of even the existence of plasma concepts, despite the fact that some of them have been known for half a century. The conclusion is that astrophysics is too important to be left in the hands of astrophysicists who have gotten their main knowledge from these textbooks. Earthbound and space telescope data must be treated by scientists who are familiar with laboratory and magnetospheric physics and circuit theory, and of course with modern plasma theory."

Due to their background, they are better able to correctly "interpret" the observations.
Hat1208
3.4 / 5 (5) Aug 15, 2013
brt

Live long and prosper
DonGateley
4 / 5 (4) Aug 15, 2013
Continued for Don:...


Thank you, thermodynamics, for an actual explanation even I can follow.
Greenwood
5 / 5 (6) Aug 15, 2013
It's one article, are you suggesting I should somehow be able to deduce the entire standard theory from reading this one specific article?


No, I'm suggesting that making claims like "circuits" can explain observation x, y and z is total nonsense when you have no evidence that it can is bad. If your pet theory is incomplete don't call me the bad guy for pointing out that it doesn't explain the evidence, it may well do someday but not today and that's all I can judge it on. Did I say "it cannot be so", no I said there isn't enough there to test or reproduce observations.

Here's a start..

Yes I can use google but you again fail to do your homework. The trouble with pulsars is the brightness temperatures are incredible, unbelievably large. The vast majority of emission mechanism cannot produce emission like that, it breaks down. So in order to say EU explains this you need an emission mechanism which you have proven can reproduce this.
vidyunmaya
1 / 5 (8) Aug 15, 2013
Sub: spread Functional Index
Plasma Regulated Electro-magnetic phenomena in magnetic Field Environment- see projections in my books and Research papers-scribd.Cosmic vision of the universe helps Comprehension.
Welcome information: This new study, based on observations from ESA's XMM-Newton X-ray space telescope, has finally found evidence that SGR 0418+5729 is indeed concealing a very strong magnetic field in its interior.
Vidyardhi nanduri-Space Cosmology Studies [Independant Research]

GSwift7
4.3 / 5 (6) Aug 16, 2013
The only evidence of black holes is how astrophysicists interpret the observations. that's why Alfven stated


Good grief.

Alfven was born in 1908. He died 18 years ago, and was 87 years old at the time. His quotes are so out of date that it's not funny. Modern cosmology embraces plasma physics to a degree Alfven could never have dreamed of. We could not maintain our modern satellite constellations if we did not understand the things Alfven complained about. His reasons for complaining are long gone. If he was still alive, he would be laughing at you.

Alfven was at his prime in the 40's and 50's. He used slide rulers for his math. None of the physical systems were properly modeled at that time because it wasn't possible to do so. In his time, most physics text books talked only about Newtonian gravity, so of course he was dismayed at the state of physics back then. It's funny how he complained about mainstream, but fought GR (the alternative of his day) tooth and nail.

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