EDP Sciences
Free access
Volume 416, Number 2, March III 2004
Page(s) 765 - 773
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20034315

A&A 416, 765-773 (2004)
DOI: 10.1051/0004-6361:20034315

Improved data for solar flare X-ray spectral analysis

K. J. H. Phillips1, J. A. Rainnie2, L. K. Harra3, J. Dubau4, F. P. Keenan4 and N. J. Peacock5

1  National Research Council Senior Research Associate, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA
2  Space Science and Technology Dept., Rutherford Appleton Laboratory, Chilton, Didcot, Oxon OX11 0QX, UK
3  Mullard Space Science Laboratory, University College London, Holmbury St Mary, Dorking, Surrey RH5 6NT, UK
4  Observatoire de Paris-Meudon, Place Jules Janssen, 92195 Meudon, France
5  EURATOM/UKAEA Fusion Association, Culham Science Centre, Abingdon, Oxon OX14 3DB, UK

(Received 12 September 2003 / Accepted 10 November 2003 )

The inclusion of collisional rates for He-like Fe and Ca ions is discussed with reference to the analysis of solar flare $\ion{Fe}{xxv}$ and $\ion{Ca}{xix}$ line emission, particularly from the Yohkoh Bragg Crystal Spectrometer (BCS). The new data are a slight improvement on calculations presently used in the BCS analysis software in that the discrepancy in the $\ion{Fe}{xxv}$  y and z line intensities (observed larger than predicted) is reduced. Values of electron temperature from satellite-to-resonance line ratios are slightly reduced (by up to 1 MK) for a given observed ratio. The new atomic data will be incorporated in the Yohkoh BCS databases. The data should also be of interest for the analysis of high-resolution, non-solar spectra expected from the Constellation-X and Astro-E space missions. A comparison is made of a tokamak $\ion{S}{xv}$ spectrum with a synthetic spectrum using atomic data in the existing software and the agreement is found to be good, so validating these data for particularly high- n satellite wavelengths close to the $\ion{S}{xv}$ resonance line. An error in a data file used for analyzing BCS $\ion{Fe}{xxvi}$ spectra is corrected, so permitting analysis of these spectra.

Key words: Sun: flares -- Sun: X-rays, gamma rays -- X-rays: spectra

Offprint request: K. J. H. Phillips, phillips@stars.gsfc.nasa.gov

© ESO 2004