Ta. Kucera et al., Wavelengths of forbidden transitions arising from levels within the Fe+19 2s(2)2p(3) ground configuration, ASTROPHYS J, 538(1), 2000, pp. 424-427
In this paper we report the identification of all remaining unidentified fo
rbidden lines arising from transitions within levels of the Fe+19 ground co
nfiguration. These lines were identified using data from the SOHO/SUMER spe
ctrograph and Skylab. Adjusted wavelength values are also given for some pr
eviously observed lines. Forbidden lines that are the result of transitions
within levels of the ground configuration of a highly ionized astrophysica
lly abundant element generally have longer wavelengths than resonance lines
emitted by the same ion. Many of these forbidden lines are fairly prominen
t in low-density plasmas and traditionally have been used in determining pr
operties of high-temperature astrophysical plasmas. The identified Fe+19 fo
rbidden lines span the 300-2665 Angstrom wavelength range. Since spontaneou
s decay rates of forbidden transitions arising from the same upper level ar
e known quite accurately, these Lines can be used for calibrating spectrome
ters over wide wavelength ranges.