Distant Magnetar Has Reliable Surface with No Atmosphere

Magnetars are neutron stars with ultra-powerful magnetic fields, which can be noticed in X-rays. Polarization measurements could give facts on their magnetic fields and area qualities. Now, astronomers making use of the NASA/ASI Imaging X-ray Polarimetry Explorer (IXPE) have observed polarized X-rays from a Galactic magnetar named 4U 0142+61 (PSR J0146+6145).

An artist’s effect of a magnetar. Picture credit rating: NASA’s Goddard Area Flight Center / S. Wiessinger.

Magnetars are neutron stars with magnetic fields that are about a quadrillion moments greater than the magnetic field of Earth.

These substantial magnetic fields are believed to be manufactured when a quickly rotating neutron star is fashioned by the collapse of the main of a huge star.

Magnetars emit bright X-rays and demonstrate erratic periods of action, with the emission of bursts and flares which can launch in just one second an volume of vitality millions of situations greater than our Sunshine emits in just one year.

Employing the IXPE observatory, University of Padova astrophysicist Roberto Taverna and colleagues detected polarized X-rays from 4U 0142+61a magnetar positioned some 13,000 mild-many years away in the constellation of Cassiopeia.

They uncovered a a lot lower proportion of polarized mild than would be predicted if the X-rays passed as a result of an atmosphere.

They also located that, for particles of mild at greater energies, the angle of polarization flipped by particularly 90 degrees as opposed to light-weight at reduce energies, subsequent what theoretical styles would forecast if the star had a sound crust surrounded by an exterior magnetosphere loaded with electrical currents.

“This was completely unforeseen. I was certain there would be an environment,” said University Faculty London’s Professor Silvia Zane.

“The star’s gas has arrived at a tipping issue and become sound in a similar way that drinking water may well convert to ice. This is a consequence of the star’s incredibly potent magnetic discipline.”

“But, like with drinking water, temperature is also a issue — a hotter gas will have to have a more robust magnetic area to turn into strong.”

“The most exciting function we could notice is the change in polarization way with energy, with the polarization angle swinging by specifically 90 degrees,” Dr. Taverna reported.

“This is in agreement with what theoretical models predict and confirms that magnetars are in truth endowed with ultra-robust magnetic fields.”

“The polarization at lower energies is telling us that the magnetic subject is possible so potent to change the environment all-around the star into a sound or a liquid, a phenomenon recognised as magnetic condensation,” reported University of Padova’s Professor Roberto Turola.

“The stable crust of the star is believed to be composed of a lattice of ions, held together by the magnetic field. The atoms would not be spherical, but elongated in the direction of the magnetic discipline.”

“It is still a subject matter of debate regardless of whether or not magnetars and other neutron stars have atmospheres.”

“Nevertheless, the new paper is the initial observation of a neutron star in which a sound crust is a trusted rationalization.”

“It is also truly worth noting that together with quantum electrodynamics effects, as we did in our theoretical modeling, gives success appropriate with the IXPE observation,” mentioned University of British Columbia’s Professor Jeremy Heyl.

“Nevertheless, we are also investigating option models to clarify the IXPE facts, for which correct numerical simulations are however missing.”

The findings seem in the journal Science,


Roberto Taverna et al, Polarized X-rays from a magnetar. Science, revealed online November 3, 2022 doi: 10.1126/science.increase0080

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