On the nature of the X-ray pulsar SAX J1324-6200

TL;DR

This paper reports recent Swift observations of the X-ray pulsar SAX J1324-6200, revealing its spin-down behavior and suggesting it is likely a low luminosity, persistent Be/neutron star binary.

Contribution

It provides improved localization, a new spin period measurement, and discusses the source's likely nature as a Be/neutron star binary.

Findings

Spin period measured at 172.84s in 2007

The pulsar is spinning down at ~6x10^-9 s s^-1

Likely classified as a low luminosity, persistent Be/neutron star binary

Abstract

We present recent observations of the X-ray pulsar SAX J1324-6200 obtained in December 2007 with the Swift satellite yielding a significant improvement in the source localization with respect to previous data and a new measurement of the spin period P=172.84s. A single object consistent in colors with a highly reddened early type star is visible in the X-ray error box. The period is significantly longer than that obtained in 1997, indicating that SAX J1324-6200 has been spinning down at an average rate of ~6x10^-9 s s^-1. We discuss the possible nature of the source showing that it most likely belongs to the class of low luminosity, persistent Be/neutron star binaries.