The insane magnetic field of magnetars.

"A simulated magnetar with magnetic field lines and surface temperature (temperature increases with color, tending from red to yellow). Credit: ©Raphaël Raynaud (LMPA/AIM/IRFU/DRF/CEA Saclay)" (ScitechDaily, Neutron Stars Gone Wild: How Magnetars Get Their Insane Magnetic Power)

There is suspicion. Cosmic radio flashes and high-energy, X- and Gamma-ray flashes from magnetars form when they impact with planets or some other massive objects. 

The neutron star forms. When the 8X larger star than the sun uses its fuel. That thing causes a situation where the star falls into the structure where electrons and protons melt together. That means those structures are purely neutrons. The neutron star's magnetic fields are insane. The thing that forms this magnetic field is the so-called Tayler-Spruit generator. In planets and stars the Tayler-Spruit generator forms a magnetic field when liquid metal rotates the metal core. 

The neutron star's mass is so high, and the material so dense that the shell and core in neutron stars cannot rotate at different speeds. Or that is very hard. So, it's possible that a neutron star that rotates in the plasma cloud can form a similar situation that the planet's metal core forms in melted metal. In stars the magnetic forms at different speeds of plasma rotation. 

The insane magnetic field of magnetars can form when some high-energy parts in a very low-mass neutron star rotate at different speeds. The magnetic field can form when the internal structures of neutron stars or neutron stars' core and neutron star shells rotate at different speeds. It's possible. That neutron star's shell and core rotate in different directions. That maximizes their mutual speed. 

"Magnetic-field lines inside the NS crust at the beginning of our NS magnetothermal simulation, that is, at t = 0. Credit: Nature Astronomy (2025). DOI: 10.1038/s41550-025-02477-y" (Sciencenewstoday, Tayler-Spruit Dynamo Mechanism Explains the Formation of Low-Field Magnetars)

There are two possible ways in which the neutron star's magnetic field can form. 

1) The rotation inside the neutron star. 

2) The plasma shield and neutron star's mutual rotation makes the magnetic field. The plasma can rotate opposite direction to the neutron star. 

That maximizes their mutual speed. The magnetar is a very low-mass neutron star and that supports the last theorem. The lower gravity field allows the plasma layer to stay more stable than around higher-mass neutron stars. Also, the plasma can explain why all low-mass neutron stars are not magnetars. 

The plasma will not fall to the neutron star if its speed is high enough, that it can remain in orbit around that thing. The insane magnetic field forms when the plasma is like strings around the neutron star. Things like whirls in the plasma can decrease the magnetic field's power. 

In some models, there is the possibility that the neutron fog is the low-density neutron structure between the neutron star's core and its shell. There is the possibility that the insane magnetic field around some neutron stars forms when plasma and the neutron fog interact together. 

Same way if there is a neutron fog between the neutron star's core and its shell, that neutron cloud or neutron fog can create its magnetic field. 

In that case, the neutron star can form an insane magnetic field. But there is another thing that can make an insane magnetic field around neutron stars. When particles like gas impact a neutron star's shell, it causes a very high-energy reaction. That reaction forms a plasma shell above a neutron star. There are nuclear reactions in that plasma. 

The neutron star rotates in that plasma. And there is the possibility that the plasma and neutron stars act like Tayler-Spruit dynamo. There the neutron star forms a stator. And plasma around it forms a rotor. If the magnetic field forms when the neutron star and its plasma rotate in opposite directions that can make a new path to the neutron star research. 

https://scitechdaily.com/neutron-stars-gone-wild-how-magnetars-get-their-insane-magnetic-power/

https://www.sciencenewstoday.org/tayler-spruit-dynamo-mechanism-explains-the-formation-of-low-field-magnetars