Comparing spectra and fitting before and after PCA applied:

notation in all plots:

single plot: black is the raw spectrum, red is the PCA reconstructed spectrum, M_ab is the mass of the BH after PCA, vari is the relative mass ratio = (M[ab]  -  M[bb]) / M[ab]. these single panels show how PCA reconstructed spectra fit the raw spectra.

double plot: the upper panel is after PCA, lower panel is before PCA applied. red is the pesudo-continuum, green is the continuum and black is the spectrum. these plots show how well the mass estimates is in both case before or after PCA applied however in calculating the parameter "vari" I assume that PCA mass is accurate.

1)  vari = 0.79 means raw mass is about 21% of the PCA-mass

below is the same as above but zoom in around 2800 Angstrom.

2) vari = 0.72 means the raw mass is about 28% of the PCA-mass.

same as above but zoomed in

 

3) vari = 0.78 means the raw mass is 22% of the PCA-mass

same as above but zoomed in

  

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4) a good example for object which PCA doesn't improve the mass estimates. vari = 0.06 means the raw mass is about 94% of the PCA-mass

same as above but zoomed in