Astronomers find the first 'wind nebula' around a magnetar

Astronomers find the first 'wind nebula' around a magnetar
This X-ray image shows extended emission around a source known as Swift J1834.9-0846, a rare ultra-magnetic neutron star called a magnetar. The glow arises from a cloud of fast-moving particles produced by the neutron star and corralled around it. Color indicates X-ray energies, with 2,000-3,000 electron volts (eV) in red, 3,000-4,500 eV in green, and 5,000 to 10,000 eV in blue. The image combines observations by the European Space Agency's XMM-Newton spacecraft taken on March 16 and Oct. 16, 2014. Credit: ESA/XMM-Newton/Younes et al. 2016

Astronomers have discovered a vast cloud of high-energy particles called a wind nebula around a rare ultra-magnetic neutron star, or magnetar, for the first time. The find offers a unique window into the properties, environment and outburst history of magnetars, which are the strongest magnets in the universe.

A neutron star is the crushed core of a massive star that ran out of fuel, collapsed under its own weight, and exploded as a supernova. Each one compresses the equivalent mass of half a million Earths into a ball just 12 miles (20 kilometers) across, or about the length of New York's Manhattan Island. Neutron stars are most commonly found as pulsars, which produce radio, visible light, X-rays and gamma rays at various locations in their surrounding magnetic fields. When a pulsar spins these regions in our direction, astronomers detect pulses of emission, hence the name.

Typical pulsar magnetic fields can be 100 billion to 10 trillion times stronger than Earth's. Magnetar fields reach strengths a thousand times stronger still, and scientists don't know the details of how they are created. Of about 2,600 neutron stars known, to date only 29 are classified as magnetars.

The newfound nebula surrounds a magnetar known as Swift J1834.9-0846—J1834.9 for short—which was discovered by NASA's Swift satellite on Aug. 7, 2011, during a brief X-ray outburst. Astronomers suspect the object is associated with the W41 supernova remnant, located about 13,000 light-years away in the constellation Scutum toward the central part of our galaxy.

Astronomers find the first 'wind nebula' around a magnetar
This X-ray image shows extended emission around a source known as Swift J1834.9-0846, a rare ultra-magnetic neutron star called a magnetar. The glow arises from a cloud of fast-moving particles produced by the neutron star and corralled around it. Color indicates X-ray energies, with 2,000-3,000 electron volts (eV) in red, 3,000-4,500 eV in green, and 5,000 to 10,000 eV in blue. The image combines observations by the European Space Agency's XMM-Newton spacecraft taken on March 16 and Oct. 16, 2014. Credit: ESA/XMM-Newton/Younes et al. 2016

"Right now, we don't know how J1834.9 developed and continues to maintain a wind nebula, which until now was a structure only seen around young pulsars," said lead researcher George Younes, a postdoctoral researcher at George Washington University in Washington. "If the process here is similar, then about 10 percent of the magnetar's rotational energy loss is powering the nebula's glow, which would be the highest efficiency ever measured in such a system."

A month after the Swift discovery, a team led by Younes took another look at J1834.9 using the European Space Agency's (ESA) XMM-Newton X-ray observatory, which revealed an unusual lopsided glow about 15 light-years across centered on the magnetar. New XMM-Newton observations in March and October 2014, coupled with archival data from XMM-Newton and Swift, confirm this extended glow as the first wind nebula ever identified around a magnetar. A paper describing the analysis will be published by The Astrophysical Journal.

"For me the most interesting question is, why is this the only magnetar with a nebula? Once we know the answer, we might be able to understand what makes a magnetar and what makes an ordinary pulsar," said co-author Chryssa Kouveliotou, a professor in the Department of Physics at George Washington University's Columbian College of Arts and Sciences.

Astronomers find the first 'wind nebula' around a magnetar
This artist's rendering shows a magnetar outburst. A 2011 outburst of Swift J1834.9-0846 led to its discovery by NASA's Swift satellite. Credit: NASA's Goddard Space Flight Center

The most famous wind nebula, powered by a pulsar less than a thousand years old, lies at the heart of the Crab Nebula supernova remnant in the constellation Taurus. Young pulsars like this one rotate rapidly, often dozens of times a second. The pulsar's fast rotation and strong magnetic field work together to accelerate electrons and other particles to very high energies. This creates an outflow astronomers call a pulsar wind that serves as the source of particles making up in a wind nebula.

"Making a wind nebula requires large particle fluxes, as well as some way to bottle up the outflow so it doesn't just stream into space," said co-author Alice Harding, an astrophysicist at NASA's Goddard Space Flight Center in Greenbelt, Maryland. "We think the expanding shell of the supernova remnant serves as the bottle, confining the outflow for a few thousand years. When the shell has expanded enough, it becomes too weak to hold back the particles, which then leak out and the nebula fades away." This naturally explains why wind nebulae are not found among older pulsars, even those driving strong outflows.

A pulsar taps into its rotational energy to produce light and accelerate its pulsar wind. By contrast, a magnetar outburst is powered by energy stored in the super-strong magnetic field. When the field suddenly reconfigures to a lower-energy state, this energy is suddenly released in an outburst of X-rays and gamma rays. So while magnetars may not produce the steady breeze of a typical pulsar wind, during outbursts they are capable of generating brief gales of accelerated particles.

Astronomers find the first 'wind nebula' around a magnetar
The best-known wind nebula is the Crab Nebula, located about 6,500 light-years away in the constellation Taurus. At the center is a rapidly spinning neutron star that accelerates charged particles like electrons to nearly the speed of light. As they whirl around magnetic field lines, the particles emit a bluish glow. This image is a composite of Hubble observations taken in late 1999 and early 2000. The Crab Nebula spans about 11 light-years. Credit: NASA, ESA, J. Hester and A. Loll (Arizona State University)

"The nebula around J1834.9 stores the magnetar's energetic outflows over its whole active history, starting many thousands of years ago," said team member Jonathan Granot, an associate professor in the Department of Natural Sciences at the Open University in Ra'anana, Israel. "It represents a unique opportunity to study the magnetar's historical activity, opening a whole new playground for theorists like me."

ESA's XMM-Newton satellite was launched on Dec. 10, 1999, from Kourou, French Guiana, and continues to make observations. NASA funded elements of the XMM-Newton instrument package and provides the NASA Guest Observer Facility at Goddard, which supports use of the observatory by U.S. astronomers.


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Jun 21, 2016
Like others, the article seeks to avoid the use of the term "electric current" -- instead opting for terms like "large particle fluxes" and "winds", which partly create the confusion which is then discussed. The sensitivity to the notion of cosmic electric currents appears in this case to even apply when large magnetic fields are readily available.

Re: "For me the most interesting question is, why is this the only magnetar with a nebula?"

The mystery is slightly lessened once the features of laboratory plasmas are considered: The plasma only glows given a particular charge density. Further, the event is likely not as rare as theorists here assume, as they've yet to consider instances where nebulae are currently thought to be illuminated by sunlight striking gas.

As observations of nebulae improve, it will become apparent that nebulae are composed of plasma filaments which can enter the plasma glow mode.

Jun 21, 2016
Rotation of the Universe falls outside the center or growing from the center outward at 100 km / sec up to 270,000 km / sec.
At the same layers in diameter increasingly smaller than the outside toward the center. For compounds are formed cyclones which do not need to have (and cyclones on Earth) significant weight or value effects are large. Also in explosion star remainder of the material from the center further accelerates (or slows down) and creates high-value effects.
However, the beautiful sounds, behavior parts of matter, like apartheid, where the laws of physics are not equal.

Jun 22, 2016
How do they determine the strength of the magnetic field of a neutron star?

Jun 22, 2016
How do they determine the strength of the magnetic field of a neutron star?


In this paper it seems they used the spindown. Most pulsars spend their lives increasing in period which is believed to be due to the emission of dipole radiation as their strong magnetic field rotates it induces very long wavelength dipole radiation. We don't observe any of this as at very long wavelength it is absorbed in the ISM. The period and the period differential give you an estimate of the minimum magnetic field or the actual magnetic field if you can estimate the angle of inclination between rotation and magnetic field.

Jun 22, 2016
sub; scientific Edge on Culture-Cosmology Vedas Interlinks
Wind-drives- at a corner- typical N-W to Hemispherical mode -beyond a structure like Red-Rectangle.
Typical distances between 2400 LY to 24-26,000 LY.Supernova-dMVT process.evidently magnetic fields are involved- operate in Neutral mode .Very few persons understand this mode- that is how Temple structures help space-cosmology studies
Think Tanks-cosmic Function of the Universe
The Concept of Big-Bang needs revision and Paradigm shift.
The Origins- Cause effect define Cosmic Pot Energy of the Universe
cosmology vedas interlinks- 15 Books available at LULU. See illustrations
pS Many thanks for the data information

Jun 22, 2016
Hi IMP-9. :)
...as their strong magnetic field rotates it induces very long wavelength dipole radiation. We don't observe any of this as at very long wavelength it is absorbed in the ISM.
Appropriately modify/apply that reasoning/known physics (re magnetic component-energy of e-m energy/field effects associated with massive spinning/orbiting features as Neut. Stars/BHs), and you will 'get' what I've LONG been pointing out about the type of energy which a binary system are 'radiating away' to account for observed decreasing system mass/orbital period decrease.

In other words: it's NOT 'g-w' but 'e-m' RADIATION which accounts for the Hulse-Taylor observations!

Once we realize this known physics explains observations of Hulse-Taylor example, then we don't 'need' to interpret NS and/or BH BINARY SYSTEM spindown 'events' as G-w radiators, but E-M-w radiators anymore!

PS: Your comments contain 'clues' to CMB radiation 'origins' etc WITHOUT Hypothetical 'BBang' etc. :)

Jun 22, 2016
Once we realize this known physics explains observations of Hulse-Taylor example


But you haven't shown that. What you have there is a hypothesis, you have not shown that it can explain the data. There exist very high quality timing datasets for a few binary pulsars, I suggest you try to build a self-consistent model before making any bold claims. GR has been shown to fit this the Hulse-Taylor binary to about 2 parts in a thousand (as well as the knowledge of observational quantities allows). You don't get to replace a model with a hypothesis which doesn't have the same explanatory power. If you seek to replace the existing interpretation then you need to do better or almost as good with fewer parameters. A simple information criterion can then be used.

And no, the CMB isn't galactic, we know that from the observation of the Sunyaev–Zel'dovich effect.

Jun 27, 2016
Hi IMP-9. :)
Once we realize this known physics explains observations of Hulse-Taylor example


But you haven't shown that. What you have there is a hypothesis, you have not shown that it can explain the data. There exist very high quality timing datasets for a few binary pulsars, I suggest you try to build a self-consistent model before making any bold claims.
Are you even aware of the (electro-)MAGNETIC FIELD ENERGIES involved in such NS features/dynamics?

If not, you are missing the whole point of what I already explained re the kind of 'radiation; which takes energy from that system and produces the mutual 'orbital decay' observed. The energy radiated takes GRAVITATIONALLY EFFECTIVE 'energy-mass' AWAY from that system. That is how 'gravity-effect 'leaves' a system like that.

Re CMB: Yes, like I said; space expanses/processes/contents are 'mixmaster' for radiation 'signals', including full gamut of 'scattering' increasing/decreasing CMB energies. :)

Jun 27, 2016
Hi Phys1. :)
I was not aware of the SZ effect, thanks IMP-9.
GR has been shown to fit this the Hulse-Taylor binary to about 2 parts in a thousand

Enough accuracy to convince any knowledgeable, psychologically stable person.
You weren't aware of a LOT of important relevant astronomical/cosmological KNOWN science facts and understandings. Which is why your obviously 'emotional' cheap shots at me fall flat on your own ignorance/misunderstandings. About time you started to listen instead of ignore, deny and insult etc, isn't it, mate?

Please read my reply to IMP-9 above re Hulse-Taylor and all such binary systems having been MISS-interpreted as 'supporting Gravity-wave' speculation/claims. And please try to avoid reading confirmation bias getting in the way of fair and objective understanding this time. :)

Jun 27, 2016
Hi Phys1. :)

I have been pointing out for years and years now all sorts of processes which produce the 'mixmaster' effect on all radiation signal wavelength/frequencies observed 'here', after traveling billions of light years, from whatever far distance source/event is being observed and whatever is already long diffused from past eons as 'background' CMB.

That you even asked that question/imply I haven't already mentioned all sorts of scattering/emission/absorbing factors which produce the 'mixmaster' effect, means that you missed it all! Either because you never saw it or because you were ignoring me.

Either way, please do not in future assume just because you never saw it, it never happened. Thanks.

Re Hulse-Taylor binary system and (electro-)Magnetic field/energy. The energy contained is humongous around one NS. Multiply that by two; and realize known interactions between such; and realize that E-M friction/radiation saps a lot of orbital energy etc. See it now? :)

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