Could SXP 1062 be an Accreting Magnetar?

TL;DR

This paper investigates whether the neutron star in SXP 1062 could be an accreting magnetar with a magnetic field exceeding 10^{14} G, based on its evolutionary history and spin-down mechanisms.

Contribution

It proposes that SXP 1062 may be an accreting magnetar and analyzes its spin-down evolution considering different initial conditions and mechanisms.

Findings

Neutron star's magnetic field may be greater than 10^{14} G.

Efficient propeller mechanisms are required for the observed spin period.

Energy conservation models for angular momentum loss are inconsistent with observations.

Abstract

In this work we explore the possible evolutionary track of the neutron star in the newly discovered Be/X-ray binary SXP 1062, which is believed to be the first X-ray pulsar associated with a supernova remnant. Although no cyclotron feature has been detected to indicate the strength of the neutron star's magnetic field, we show that it may be $\ga 10^{14} $G. If so SXP 1062 may belong to the accreting magnetars in binary systems. We attempt to reconcile the short age and long spin period of the pulsar taking account of different initial parameters and spin-down mechanisms of the neutron star. Our calculated results show that, to spin down to a period $\sim 1000 $s within $10-40 $kyr requires efficient propeller mechanisms. In particular, the model for angular momentum loss under energy conservation seems to be ruled out.