RXTE and XMM observations of intermediate polar candidates

TL;DR

This study used RXTE and XMM observations to confirm one new intermediate polar, V2069 Cyg, among nine candidates by analyzing their X-ray timing and spectral properties, advancing the identification of magnetic cataclysmic variables.

Contribution

The paper provides the first confirmation of V2069 Cyg as a hard X-ray selected intermediate polar through detailed timing and spectral analysis.

Findings

V2069 Cyg confirmed as a genuine intermediate polar with a 743.2 s pulse period.

IGR J00234+6141 shows consistent 563.5 s pulse period with previous detections.

IGR J14536-5522 shows no coherent modulation at 3.1 hr period, but harmonic signals were observed.

Abstract

Aims. To determine the credentials of nine candidate intermediate polars in order to confirm whether or not they are magnetic cataclysmic variables. Methods. Frequency analysis of RXTE and XMM data was used to search for temporal variations which could be associated with the spin period of the magnetic white dwarf. X-ray spectral analysis was carried out to characterise the emission and absorption properties of each target. Results. The hard X-ray light curve of V2069 Cyg shows a pulse period of 743.2 s, and its spectrum is fit by an absorbed bremsstrahlung model with an iron line, confirming this to be a genuine intermediate polar. The hard X-ray light curve of the previously confirmed intermediate polar IGR J00234+6141 is shown to be consistent with the previous low energy X-ray detection of a 563.5 s pulse period. The likely polar IGR J14536-5522 shows no coherent modulation at the previously identified period of 3.1 hr, but does exhibit a clear signal at periods likely to be harmonically related to it. Whilst our RXTE observations of RX J0153.3+7447, Swift J061223.0+701243.9, V436 Car and DD Cir are largely too faint to give any definitive results, the observation of IGR J16167-4957 and V2487 Oph show some characteristics of intermediate polars and these objects remain good candidates. Conclusions. We confirmed one new hard X-ray selected intermediate polar from our sample, V2069 Cyg.