Theoretical analysis of iron X-ray spectra observed in solar active region

The theoretical analysis of X-ray spectra observed by the Flat Crystal Spectrometer of the Solar Maximum Mission in the 13A-19A wavelength range is presented. The emission lines correspond to Fe ions (Fe XVI, Fe XVII, Fe XVIII) and some O-ions (O VII,O VIII). The fitting of a synthetic spectrum to the observed one shows that it is difficult to represent the emissive region with one temperature model.