Astronomy & Astrophysics

Free access article

A&A 389, 228-238 (2002)
DOI: 10.1051/0004-6361:20020529

High-resolution X-ray spectroscopy of Procyon by Chandra and XMM-Newton

A. J. J. Raassen^{1, 2}, R. Mewe¹, M. Audard³, M. Güdel³, E. Behar⁴, J. S. Kaastra¹, R. L. J. van der Meer¹, C. R. Foley⁵ and J.-U. Ness⁶

¹ SRON National Institute for Space Research, Sorbonnelaan 2, 3584 CA Utrecht, The Netherlands
² Astronomical Institute "Anton Pannekoek", Kruislaan 403, 1098 SJ Amsterdam, The Netherlands
³ Paul Scherrer Institut, Würenlingen & Villigen, 5232 Villigen PSI, Switzerland
⁴ Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027, USA
⁵ Mullard Space Science Laboratory, University College London, Surrey, RH5 6NT, UK
⁶ Universität Hamburg, Gojenbergsweg 112, 21029 Hamburg, Germany

(Received 27 August 2001 / Accepted 5 April 2002 )

Abstract
We report the analysis of the high-resolution soft X-ray spectrum of the nearby F-type star Procyon in the wavelength range from 5 to 175 Å obtained with the Low Energy Transmission Grating Spectrometer (LETGS) on board Chandra and with the Reflection Grating Spectrometers (RGS) and the EPIC-MOS CCD spectrometers on board XMM-Newton. Line fluxes have been measured separately for the RGS and LETGS. Spectra have been fitted globally to obtain self-consistent temperatures, emission measures, and abundances. The total volume emission measure is ${\sim} 4.1 \times 10^$ cm ^-3 with a peak between 1 and 3 MK. No indications for a dominant hot component ( $T \gtrsim 4$ MK) were found. We present additional evidence for the lack of a solar-type FIP-effect, confirming earlier EUVE results.

Key words: stars: individual: Procyon, $\alpha$ Canis Minoris -- stars: coronae -- stars: late-type -- stars: activity -- X-rays: stars

Offprint request: A. J. J. Raassen, a.j.j.raassen@sron.nl