Application of Laboratory and Modeling Capabilities to Extreme Ultraviolet Spectroscopy of Astrophysical Sources

摘要

Work funded by the subject LDRD proposal has produced the following results. First, a comprehensive catalog of EUV lines from M-shell iron (Fe IX-XVI) in the 60-140 {angstrom} waveband. Second, a revised estimate of the radiative cooling of high-temperature plasmas by Fe, which dominates the cooling in cosmic-abundance plasmas from 4 x 10{sup 5}K to 1 x 10{sup 7}K. Third, laboratory data to correct theoretical atomic models and develop reliable spectral models of M-shell Fe in the EUV. Fourth, a solution of the origin of the quasi-continuum in EUV spectra of late-type stars, which has been variously ascribed to a high-temperature tail on the emission measure distribution of stellar coronae, reduced metal abundances, resonant scattering (destruction) of emission lines, and incompleteness of atomic models.