RXTE confirmation of the Intermediate Polar status of Swift J0732.5-1331

TL;DR

This study confirms Swift J0732.5-1331 as an intermediate polar by analyzing RXTE X-ray data, identifying its spin period, spectral characteristics, and ruling out the orbital period modulation.

Contribution

The paper provides the first detailed X-ray analysis confirming the intermediate polar status of Swift J0732.5-1331 using RXTE data.

Findings

Confirmed X-ray spin period of 512.4 seconds.

Detected a 37 keV bremsstrahlung continuum.

Identified a 6.4 keV iron emission line.

Abstract

Aims. We intend to establish the X-ray properties of Swift J0732.5-1331 and therefore confirm its status as an intermediate polar. Method. We analysed 36,240 s of X-ray data from RXTE. Frequency analysis was used to constrain temporal variations and spectral analysis used to characterise the emission and absorption properties. Results. The X-ray spin period is confirmed to be 512.4(3) s with a strong first harmonic. No modulation is detected at the candidate orbital period of 5.6 h, but a coherent modulation is present at the candidate 11.3 h period. The spectrum is consistent with a 37 keV bremsstrahlung continuum with an iron line at 6.4 keV absorbed by an equivalent hydrogen column density of around 10^22 atoms cm^-2. Conclusions. Swift J0732-1331 is confirmed to be an intermediate polar.