Dear all,
Abundance measurements in Active Region Cores
Interestingly, a re-analysis of the good old SMM/FCS observations of quiescent active region cores, using up-to-date atomic data, confirms earlier results based on Hinode/EIS (Del Zanna 2013, A&A, 555, A47).
The Fe/Ne and Fe/O ratios are remarkably similar for different ARs, with an FIP bias of about 3, the same as was found in terms of Fe/Ar and Fe/S for a few ARs from Hinode EIS (Del Zanna 2013,A&A, 558, A73). These abundances are different from previous results by other authors, but apply only to the hot (about 3 MK) AR core loops.
In terms of emission above 3 MK, the SMM/FCS results are also in agreement with previous results from Hinode EIS, with a sudden drop in the emission measure for higher temperatures, and very little Fe XVIII emission.
The MAGIXS instrument would provide an excellent opportunity to combine simultaneous EUV and X-ray spectroscopy of ARs, and to study further these diagnostics.
The A&A paper is available at http://adsabs.harvard.edu/abs/2014A%26A...565A..14D and a preprint at http://solar.physics.montana.edu/cgi-bin/eprint/index.pl?entry=23180
Giulio and Helen