Figure 4. Comparison between the higher-S/N FUSE 2002 and the deconvolved COS 2010 IRAS F22456−5125 spectra in the rest frame O vi region. While the continuum level in 2010 is 17% higher than in the 2002 FUSE observation, the absorption trough profile in the red component does not show significant changes given the limited S/N of the FUSE observation and the larger aperture used by the latter. Changes in the blue line profile seem to be observed in the blue component of the O vi doublet; however, the line profile is located at their edge of the COS detector in a region where the S/N is lower and the wavelength solution is inaccurate.
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