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A Multiwavelength Study of RZ Cassiopeiae: The XMM-Newton/VLA Campaign

Marc Audard·Julius R. Donisan·Manuel Guedel
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Abstract

XMM-Newton and the VLA simultaneously observed the eclipsing Algol-type binary RZ Cassiopeiae in August 2003. The secondary eclipse (K3 IV companion behind the A3 V primary) was placed at the center of the 15-hour radio campaign, while the X-ray satellite monitored a full 1.2-day orbital period. We present results of the X-ray and radio campaigns. The X-ray light curve shows significant modulation probably related to rotational modulation and active region evolution, and even small flares. However, the X-ray eclipse is not deep, implying that the coronal X-ray emitting material is spatially extended. The Reflection Grating Spectrometer (RGS) spectrum shows a variety of bright emission lines from Fe, Ne, O, N. A strong [C/N] depletion probably reflects the surface composition of the secondary which fills its Roche lobe and loses material onto the primary. The O~\textsc{vii} He-like triplet reflects a low forbidden-to-intercombination ratio; while it generally suggests high electron densities, the ratio is here modified by photoexcitation by the strong UV flux of the primary A3 V star. The radio light curve shows no similarity to the X-ray light curve. The eclipse timings are different, and the radio flux increased while the X-ray flux decreased. The radio spectral slope is shallow ($α= 0 - 1$).

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Marc Audard, Julius R. Donisan, Manuel Guedel. 2004-09-21. A Multiwavelength Study of RZ Cassiopeiae: The XMM-Newton/VLA Campaign. https://arxiv.org/abs/astro-ph/0409520

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