Magnetars:The Universe's Monster Magnets, page 1

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Topic started on 6-2-2005 @ 03:32 AM by Vajrayana

I've read a lot about neutron stars,and flashing pulsars being the lighthouses of the galaxy,but I wasn't aware of this neutron star of special distinction:

The Magnetar

First discovered in 1998,only 10 AXPs (Anomalous X-ray Pulsar) or "Magnetar(s)" have been found so far,far rarer in comparison to the 1500 known normal pulsars.
First a little info on pulsars:

Pulsars, are known to have intense magnetic fields and to emit directional beams of strong pulses, best observed by radio astronomy but also very evident in the X-ray region, in extremely regular intervals (with periods from about 1/1000th of a second to several seconds) whose cyclical nature is related to their (often rapid) rotation; the Earth must lie within the beam's solid angle in order to detect this Pulsar action (the pulses therefore are bursts of radiation from a constant beam detected intermittently from Earth, much like a searchlight's beam, while sweeping continuously, appears to the viewer only when aligned momentarily as it passes through its cycle)

All found here:
rst.gsfc.nasa.gov...

Pulsars can spin around several times a second, flashing the galaxy with beams of radio waves.Magnetars flash X-rays,and at a slower rate - about once every 10 seconds, while occasionally letting out a burst of gamma rays.

A rotating magnet gives off energy, and the greater the magnetic field, the faster the energy loss.

Magnetars exhibit rapid deceleration, which implies a huge magnetic field,so powerful in fact that it is thousands of times stronger than that of normal pulsars and billions of times stronger than any magnet on Earth. In fact,
Magnetars possess the highest magnetic fields in the universe!!:

Most neutron stars have very strong magnetic fields up to 1012 gauss (a normal star's field has a strength of around 100 gauss)

A Magnetar or

An AXP has a magnetic field measuring around 1014 Gauss (the current record holder, at 1015 Gauss, is SGR 1806-20, about 1000 times greater than a typical neutron star and a million billion times that of the Sun's 5 Gauss. A magnetar is similar to an SGR (Soft Gamma-ray Repeaters), another neutron star variant that undergoes periodic variations in energy output. Both AXPs and SGRs are detected by their pronounced X-ray signals. The Rossi Explorer satellite is used to study neutron stars. One magnetar, N 39, has been imaged by the HST and appears in the visible as a collection of filamentous strands formed from shock waves released when a giant star exploded some thousands of years ago.

More info on pulsars and magnetars can be found here:
rst.gsfc.nasa.gov...

Origin of the Magnetar

Magnetars and pulsars belong to a class of objects called neutron stars, which are big balls of tightly packed neutrons no larger than a big city.

Here's how they form: When stars above about eight solar masses run out of fuel to burn, they explode in what is called a supernova. What remains can collapses into a neutron star.

To have such large magnetic fields, magnetars are thought to originate from the supernova of very massive stars.

Scientists have recently found evidence of these origins from massive star supernova while studying a magnetar called 1E 1048.1-5937, located 9,000 light-years away in the constellation Carina,discovering evidence that the original star,from which the magnetar formed, had a mass 30 to 40 times that of the Sun - a very rare size for a star.

Gaensler and his colleagues have found evidence for this in an enormous void -- more than 70 light-years across -- that showed up in their radio data.

"The empty bubble is exactly centered on the magnetar and it is expanding," Gaensler said.

He explained that the magnetar's radiation cannot be the cause of the cavity, since that would require the absorption of too many of the X-rays that are seen. Instead, a stellar wind from the progenitor star of the magnetar must have cleared out the gas.

This wind would have been five times faster than the Sun's wind of charged particles -- the source of space weather and the Northern Lights -- and a million times denser. The implied energy is 25 million times that of our solar wind.

It takes a very massive star, some 30 to 40 solar masses, to generate such a powerful gust. If this is the correct explanation, then the progenitor star lived 5-6 million years before it exploded -- creating the magnetar in its ashes. (Massive stars die young. Our middle-ages Sun, by comparison, is about 4.6 billion years old.)

Magnetars on a crash diet?

In sweeping out the huge bubble around it, the heavy star blew off 2 to 3 solar masses of material. But even losing 10 percent of its mass in this way, the supernova remnant would have been too heavy to form a neutron star and would instead have collapsed into a black hole, theory holds.

"Astronomers used to think that really massive stars formed black holes when they died," said Simon Johnston from the Australia Telescope National Facility. "But in the past few years we've realized that some of these stars could form pulsars, because they go on a rapid weight-loss program before they explode as supernovae."

Gaensler said that, at the very end of its life, the star likely lost 90 percent of its mass, which would make it skinny enough to become a neutron star, as opposed to a black hole.

also:

"We do know these magnetars are an adolescent stage of neutron stars,"

If magnetars arise out of more massive stars, then only 10 percent of neutron stars will go through the magnetar stage -- ruling out some theories that all pulsars spend some time as magnetars.

More info from rest of the article here:
www.cnn.com...
Additional Source & Findings

I find these existing magnetic fields power of attraction almost unimaginable.
In theory,I would think if one of these super magnetars ever approached an event horizon of a black hole it would provide a grand visual of the Universe's epic version of duel to the death,before the magnetar succumbing to speghettification.Any cosmologists or physics majors out there that could more accurately predict the theoretical outcome of such a gravitational clash of the titans?Would the magnetar's magnetic field be a factor in resisting/assisting speghettification from the black hole's gravity?or would a different phenomena of demise occur,surprise end game scenario?or in theory could the clash ever occur at all?impossible delusions from a space cadet?

[edit on 6-2-2005 by Vajrayana]

reply posted on 6-2-2005 @ 11:30 AM by beyondSciFi

Wow this was an interesting read, very nice research, u get my "way above" vote.

reply posted on 6-2-2005 @ 09:12 PM by Vajrayana

Thank you for the vote and sharing an interest beyondSciFi... I did some further research today regarding possible scenarios of a neutron star/pulsar/magnetar colliding with a black hole.In astrophysics,the scenario is known as a NS-BH merger or more often a NS-BH(Neutron Star-Black Hole) binary, so I guess AXP-BH or MS-BH could apply for an Anomalous X-ray Pulsar aka Magnetar - Black Hole showdown.Although such an occurrence has yet to be proven,their possible detection rests in the evidence of "afterglows" or GRB(s) (Gamma Ray Bursts) or GRB Progenitors,back in May 1997 Keck telescopes detected an afterglow/GRB with a red shift of z=.835 indicating the GRB originated from a "cosmological" distance-a possible candidate for a binary.Presently it is a monumental task just to identify Neutron Star-Neutron Star(NS-NS) binaries or binary pulsars,with detection of a NS-BH being exponentionally more difficult by >~10-100,probably making detection of a Magnetar-Black Hole binary nearly impossible with present technology. Also events leading up to GRB explosions hold the greatest promise of releasing,as yet undetected gravitational waves. Currently there are gravitational wave detectors in development that will help us differentiate these binaries : LISA (Laser Interferometor Space Antenna), which is an ESA-NASA project expected to launch in 2011, also LIGO(Laser Interferometer Gravitational Wave Observatory),a joint project of Caltech and MIT.Also 2 favored mathematical methods scientists are developing to help understand these phenomena are DAMR(Distributed Adaptive Mesh Refinement-an alogorithm by which improved resolution(over initial grid) is added where and when needed,also incorporating modified Newtonian code for GeneraL Relativistic Hydrodynamic equations & SPH(Smoothed Partical Hydrodynamics).Also I searched the net a long time looking for any animated simulation that could slightly resemble a Magnetar-Black Hole showdown I envisioned-one of a Magnetar resisting but eventually being tidally ripped apart by the black hole gravitation...showing mass transfer depiction & angular momentum losses with possible accretion disc structure forming...but presently even mega-tera-flop-supercluster supercomputers are not powerful enough even for a NS-BH binary 3-D simulation due to the evolutions of the binary requiring tremendous amounts of storage,requiring huge numbers of floating point operations,the resolving of nonlinear distortions of the black hole(small fractions of M),as well as taking into account outgoing gravitational waves.Here is the best simulation of a possible Magnetar-Black Hole showdown I could find:

www.phys.lsu.edu...
(Requires Quicktime)

[edit on 6-2-2005 by Vajrayana]

reply posted on 6-2-2005 @ 10:47 PM by Jehosephat

Reminds me of Robert L Forwards "Dragons Egg" series which featured life on a nuetron star fun read.

I would be more interesting to see what happens when 2 of these things collide.. and how much gets irradiate around it

reply posted on 7-2-2005 @ 03:52 AM by E_T

I wouldn't think collision of black hole and magnetar so different than collision with normal neutron star, it's amount of falling matter which affects to power of "burp"... but of course strong magnetic field "might" cause some nice effects to matter already in accretion disk/and to its radiation.

Also considering gravity waves it's small and massive objects (orbiting each others in small orbits) which cause those so also in that area it should be close to normal neutron stars.

As mentioned previously, magnetars have a magnetic field of above 10 gigatesla, strong enough to wipe a credit card from the distance of the Sun from the Earth and strong enough to be fatal from the distance of the Moon. By comparison, Earth's natural magnetic field is 50 microtesla, and on Earth a fatal magnetic field is only a theoretical possibility; some of the strongest fields generated are actually used in medical imaging. A small neodymium based rare earth magnet has a field of about a tesla, and most media used for data storage can be erased with millitesla.

en.wikipedia.org...

“If this magnetar took the place of our moon, its magnetic field would strip the Earth of every piece of metal and rearrange the molecules in our bodies,”

www2.gwu.edu...!/magnetar.html

spaceflightnow.com...
science.nasa.gov...
www.sff.net...

Here's very good page:
`MAGNETARS', SOFT GAMMA REPEATERS & VERY STRONG MAGNETIC FIELDS
Physicists have not made steady fields stronger than 4.5 x 10E5 Gauss in the lab because the magnetic stresses of such fields exceed the tensile strength of terrestrial materials. If you try to make stronger fields, magnetic forces will blow apart your electromagnet.
Using chemical high explosives to drive implosions, it is possible to compress a magnetic field and reach higher field strengths, at least for a tiny fraction of a second. This has been done at Los Alamos Laboratory in the U.S., and at a nuclear weapons lab in Sarov, Russia, attaining fields of about 10E7 Gauss before the equipment was destroyed.
So could be said that nature has exclusive rights to these magnetic fields.