In A First, Scientists Discover ‘Wind Nebula’ Around An Ultramagnetic Neutron Star

mwn_xmm_labels — This X-ray image shows extended emission around a source known as Swift J1834.9-0846, a rare ultramagnetic 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. ESA/XMM-Newton/Younes et al.

The cosmos we live in is home to several mysteries. Even so, magnetars — exotic neutron stars with extremely strong magnetic fields — would definitely push the envelope when it comes to the rare, the quirky and the bizarre.

A new discovery has now added to the mystery surrounding these incredibly rare neutron stars. For the first time ever, scientists have detected a vast cloud of high-energy particles called a “wind nebula” surrounding a magnetar — in this case, a magnetar named J1834.9 located roughly 13,000 light-years away near the central part of our galaxy.

“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,” George Younes, a postdoctoral researcher at George Washington University in Washington, D.C., and lead author of a study to be published in the Astrophysical Journal, said in a statement. “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.”

Pulsars are rotating neutron stars, which are immensely dense stars created as a result of a massive star collapsing in on itself. As a pulsar rotates, it emits high-energy radiation into the cosmic void, similar to a lighthouse casting beams of light. If this beam of high-energy radiation is pointed toward the Earth, the pulsars can be detected using telescopes.

430453main_crabmosaic_hst_big_full — 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. NASA, ESA, J. Hester and A. Loll (Arizona State University)

The magnetic fields produced by pulsars can be 100 billion to 10 trillion times stronger than Earth’s. Magnetar fields, meanwhile, are a thousand times stronger.

However, scientists still don’t know the details of how the magnetar fields are created — primarily because these structures are incredibly rare. Of the roughly 2,600 neutron stars known to date, only 29 are classified as magnetars.

That is why the discovery of a wind nebula — which is created around a pulsar when its fast rotation and strong magnetic field interact to accelerate electrons and other particles to very high energies — around a magnetar assumes special importance. The discovery may provide scientists the much-needed clues to the birth, evolution and properties of magnetars, which, unlike pulsars, are capable of generating only brief bursts of accelerated particles.

“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,” co-author Chryssa Kouveliotou, a professor at George Washington University’s Columbian College of Arts and Sciences, said in the statement.