Solar spectroscopy in the far-ultraviolet–x-ray wavelength regions: status and prospects

We review the status and prospects of solar spectroscopy in the far-UV–x-ray wavelength regions between approximately 1.7 and 2000 Å. We divide the solar spectrum into a number of wavelength regions, determined by characteristics of spectroscopic instrumentation. The quality of the available spectra obtained in each region is discussed, concentrating on spectral resolution, wavelength coverage and accuracy, and line intensity and line-profile information. We limit the discussion primarily to papers that contain lists of spectral lines such that a global view of a given spectral region can be obtained. Plasma diagnostics and line identifications are not discussed because these topics have been reviewed many times previously. We discuss the need for absolute wavelength and line-profile information and briefly mention plans for future spectroscopic investigations for those cases for which information is available. We summarize by giving our opinion of the best available spectral line lists.