EDP Sciences
Free access
Volume 370, Number 3, May II 2001
Page(s) 1071 - 1087
Section The Sun
DOI http://dx.doi.org/10.1051/0004-6361:20010255

A&A 370, 1071-1087 (2001)
DOI: 10.1051/0004-6361:20010255

A comparison between theoretical and solar FeXII UV line intensity ratios

A. M. Binello1, E. Landi2, H. E. Mason1, P. J. Storey3 and J. W. Brosius4

1  Department of Applied Mathematics and Theoretical Physics, University of Cambridge, UK
2  Naval Research Laboratory, Washington DC, 20375, USA
3  Department of Physics and Astronomy, University College London, Gower Street, London WC1E 6BT, UK
4  Raytheon ITSS, Laboratory for Astronomy and Solar Physics, Code 682.1, NASA's Goddard Space Flight Center, Greenbelt, MD 20771, USA

(Received 18 December 2000 / Accepted 13 February 2001 )

A new set of radiative and electron collisional data for Fe XII was presented in two earlier papers. In the present work, we derive level populations and theoretical line intensities for a range of plasma densities and temperatures. Observations of Fe XII lines obtained with the Solar EUV Rocket Telescope and Spectrograph are analysed both as a check the quality of the new atomic data and to determine the electron density in active regions and the quiet Sun. The discrepancy between the electron density values determined from FeXII line intensity ratios and those obtained from other ions is investigated.

Key words: Sun: general -- atomic data -- UV Sun: radiations -- plasmas

Offprint request: E. Landi, landi@poppeo.nrl.navy.mil

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