Letter to the Editor

RXTE confirmation of the intermediate polar status of IGR J15094–6649

¹ Department of Physics and Astronomy, University of Leicester, Leicester LE1 7RH, UK e-mail: oliver.butters@star.le.ac.uk
² Department of Physics and Astronomy, The Open University, Walton Hall, Milton Keynes MK7 6AA, UK
³ CRESST and X-ray Astrophysics Laboratory NASA/GSFC, Greenbelt, MD 20771, USA
⁴ Department of Physics, University of Maryland, Baltimore County, 1000 Hilltop Circle, Baltimore, MD 21250, USA

Received: 26 January 2009
Accepted: 13 March 2009

Abstract

Aims. We aim to establish the X-ray properties of the intermediate polar candidate IGR J15094–6649 and therefore confirm its inclusion into the class.

Methods. 42 856 s of X-ray data from RXTE was analysed. Frequency analysis was used to constrain temporal variations and spectral analysis used to characterise the emission and absorption properties.

Results. A spin period of 809.7 ± 0.6 s is present, revealed as a complex pulse profile whose modulation depth decreases with increasing X-ray energy. The spectrum is well fitted by either a 17 ± 4 keV Bremsstrahlung or Γ = 1.8 ± 0.1 power law, with an iron emission line feature and significant absorption in each case.

Conclusions. IGR J15094–6649 is confirmed to be an intermediate polar.