CDS/TRACE Observations of transition region lines(2.6)
Contribution from O VI 173 Å lines[
Based on the observed spectra and the wavelength response of the TRACE 171 Å channel we estimate that the O VI lines contribute roughly 10% to the observed intensities.
If the oscillation in the 171 Å channel were caused by oscillations in the sunspot transition region, the O VI lines would have to oscillate with an amplitude exceeding 23, 38, and 33 percent in NOAA 9433, 9436 and 9441, respectively.
Based on the NIS observations the amplitudes in the O VI lines should be < 10%