The timing behavior of magnetar Swift J1822.3-1606: timing noise or a decreasing period derivative?

TL;DR

This paper investigates the complex timing behavior of magnetar Swift J1822.3-1606, attributing observed variations to both timing noise and a decreasing period derivative, likely caused by wind braking.

Contribution

It provides a theoretical analysis showing that the magnetar's timing variations are due to both noise and a decreasing period derivative, advancing understanding of magnetar timing behavior.

Findings

Timing solutions are affected by both noise and decreasing period derivative.

The decreasing period derivative may be caused by wind braking.

Future observations are needed to confirm the trend of the period derivative.

Abstract

The different timing results of the magnetar Swift J1822.3-1606 is analyzed and understood theoretically. It is pointed that different timing solutions are caused not only by timing noise, but also that the period derivative is decreasing after outburst. Both the decreasing period derivative and the large timing noise may be originated from wind braking of the magnetar. Future timing of Swift J1822.3-1606 will help us make clear whether its period derivative is decreasing with time or not.