Ejector and propeller spin-down: How might a superluminous supernova millisecond magnetar become the 6.67 hr pulsar in RCW103

TL;DR

This paper presents a model explaining how a superluminous supernova magnetar could evolve into a long-period pulsar through interactions with a remnant disk, accounting for its extreme magnetic field and slow spin.

Contribution

It introduces a novel spin-down mechanism involving ejector and propeller phases driven by a remnant disk, explaining the unique properties of 1E 161348-5055.

Findings

The magnetar has an estimated magnetic field of ~5x10^15 G.

The remnant disk mass is approximately 10^24 g.

The model accounts for the observed 6.67 hr spin period and 1-3 kyr age.

Abstract

The X-ray source 1E 161348-5055 in the supernova remnant RCW 103 recently exhibited X-ray activity typical of magnetars, i.e. neutron stars with magnetic fields > 10^14-10^15 G. However, 1E 161348-5055 has an observed period of 6.67 hr, in contrast to magnetars which have a spin period of seconds. Here we describe a simple model which can explain the spin evolution of 1E 161348-5055, as well as other magnetars, from an initial period of milliseconds that would be required for dynamo generation of magnetar-strength magnetic fields. We propose that the key difference between 1E 161348-5055 and other magnetars is the persistence of a remnant disk of small total mass. This disk caused 1E 161348-5055 to undergo ejector and propeller phases in its life, during which strong torques caused a rapid increase of its spin period. By matching its observed spin period and ~1-3 kyr age, we find that 1E 161348-5055 has the (slightly) highest magnetic field of all known magnetars, with B~5x10^15 G, and that its disk had a mass of ~10^24 g, comparable to that of the asteroid Ceres.