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XMM-Newton observations of the ultra-compact binary RX J1914+24

Gavin Ramsay·Pasi Hakala·Kinwah Wu·Mark Cropper·K. O. Mason·F. A. Cordova·W. Priedhorsky
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Abstract

We present XMM-Newton observations of the 569 sec period system RX J1914+24 (V407 Vul). This period is believed to represent the binary orbital period making it an ultra-compact binary system. By comparing the phase of the rise to maximum X-ray flux at various epochs (this includes observations made using ROSAT, ASCA and Chandra) we find that the system is spinning up at a rate of 3.17+/-0.07x10^{-12} s/s. We find that the spectra softens as the X-ray flux declines towards the off-phase of the 569 sec period. Further, the spectra are best fitted by an absorbed blackbody component together with a broad emission feature around 0.59keV. This emission feature is most prominent at the peak of the on-phase. We speculate on its origin.

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Gavin Ramsay, Pasi Hakala, Kinwah Wu, Mark Cropper, K. O. Mason, F. A. Cordova, W. Priedhorsky. 2004-12-13. XMM-Newton observations of the ultra-compact binary RX J1914+24. https://doi.org/10.1111/j.1365-2966.2005.08574.x

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