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A&A 365, L324-L328 (2001)
DOI: 10.1051/0004-6361:20000047

First light measurements with the XMM-Newton reflection grating spectrometers: Evidence for an inverse first ionisation potential effect and anomalous Ne abundance in the Coronae of HR 1099

A. C. Brinkman¹, E. Behar², M. Güdel³, M. Audard³, A. J. F. den Boggende¹, G. Branduardi-Raymont⁴, J. Cottam², C. Erd⁵, J. W. den Herder¹, F. Jansen⁵, J. S. Kaastra¹, S. M. Kahn², R. Mewe¹, F. B. S. Paerels², J. R. Peterson², A. P. Rasmussen², I. Sakelliou⁴ and C. de Vries¹.

¹  Space Research Organization of The Netherlands, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
²  Columbia Astrophysics Laboratory, Columbia University, 550 West 120th Street, New York, NY 10027, USA
³  Paul Scherrer Institute, Würenlingen and Villigen, 5235, Switzerland
⁴  Mullard Space Science Laboratory, University College London, Dorking RH5 6NS, UK
⁵  Astrophysics Division, Space Science Department of ESA, ESTEC, 2200 AG Noordwijk, The Netherlands

(Received 2 October 2000 / Accepted 24 October 2000)

Abstract
The RS CVn binary system HR 1099 was extensively observed by the XMM-Newton observatory in February 2000 as its first-light target. A total of 570 ks of exposure time was accumulated with the Reflection Grating Spectrometers (RGS). The integrated X-ray spectrum between 5-35 Åis of unprecedented quality and shows numerous features attributed to transitions of the elements C, N, O, Ne, Mg, Si, S, Fe, and Ni. We perform an in-depth study of the elemental composition of the average corona of this system, and find that the elemental abundances strongly depend on the first ionisation potential (FIP) of the elements. But different from the solar coronal case, we find an inverse FIP effect, i.e., the abundances (relative to oxygen) increase with increasing FIP. Possible scenarios, e.g., selective enrichment due to Ne-rich flare-like events, are discussed.

Key words: atomic processes -line: formation -nuclear reactions, nucleosynthesis, abundances -stars: coronae -stars: individual (HR 1099) - X-rays: stars

Offprint request: B. Brinkman

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