PCA of PCA: Principal Component Analysis of Partial Covering Absorption in NGC 1365

  title={PCA of PCA: Principal Component Analysis of Partial Covering Absorption in NGC 1365},
  author={Michael L. Parker and Dominic J. Walton and Andrew C. Fabian and Guido Risaliti},
  journal={Monthly Notices of the Royal Astronomical Society},
We analyse 400 ks of XMM–Newton data on the active galactic nucleus NGC 1365 using principal component analysis (PCA) to identify model-independent spectral components. We find two significant components and demonstrate that they are qualitatively different from those found in MCG–6-30-15 using the same method. As the variability in NGC 1365 is known to be due to changes in the parameters of a partial covering neutral absorber, this shows that the same mechanism cannot be the driver of… 

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