Curated by RSF Research Staff
Neutron star jets challenge theory!
We see jets of ionized matter in all types of astrophysical objects from the plasma jets seen emanating from the surface of stars like our Sun (read more here) to the relativistic jets emanating from black holes. The energy of these jets and relativistic nature depends on the nature of the object and the location of the jet formation – with the most prominent generally emanating from the polar regions as extended beams along the axis of rotation.
However, although these jets are observed in some neutron stars, they have never been observed in highly magnetized neutron stars. This phenomenon has previously led theorists to conclude that magnetic fields inhibit their formation. Subsequent theories suggested that jet formation in neutron stars invoke a magneto-centrifugal launch mechanism which launches the jet from the innermost accretion disk along the magnetic flow dynamic – the magnetic field lines. It was therefore suggested that in highly magnetized neutrons stars the magnetic field would dominate over the disk pressure such that there would be no inner accretion to launch the jet.
A straightforward explanation it would seem – but not anymore.
Utilizing data from Very Large Array radio telescope in New Mexico and NASA's Swift space telescope a team led by Jacob van den Eijnden at the University of Amsterdam, observed radio emission indicative of relativistic jets from the neutron star, Swift J0243.6+6124. Theses result contradict the existing ideas about jet formation in neutron stars and indicate that either the jet-launching region must be much farther from the neutron star than previously thought or jet formation models need to be revisited.