Ultraluminous X-ray pulsar: accreting magnetar?

TL;DR

This paper explores the possibility that the ultra-luminous X-ray pulsar NuSTAR J095551+6940.8 is an accreting magnetar with complex magnetic field structures, suggesting a new class of neutron stars with implications for binary evolution.

Contribution

It proposes that the ultra-luminous X-ray pulsar may be an accreting magnetar with multipole magnetic fields, expanding the understanding of neutron star magnetic configurations.

Findings

NuSTAR J095551+6940.8 may be an accreting magnetar.

The pulsar could have a multipole field of 10^14 G.

This phase may lead to the formation of massive millisecond pulsars.

Abstract

Magnetars are a special kind of neutron stars. There may also be accreting magnetars. From the studies of isolated magnetars, it is known that a neutron star with a strong dipole field only is not a magnetar. Super-slow X-ray pulsars may just be accreting high magnetic field neutron stars. The ultra-luminous X-ray pulsar NuSTAR J095551+6940.8 may be an accreting magnetar. It may be an accreting low magnetic field magnetar with multipole field of 10^14 G and dipole field of 10^12 G. This point of view is consistent with the study of isolated magnetars. An ultra-luminous X-ray pulsar phase in the binary evolution may result in massive millisecond pulsars.