A critical evaluation of PCA detection of polarized signatures using real stellar data

Abstract

The general context of this study concerns the post-processing of multiline spectropolarimetric observations of stars, and in particular these numerical analysis techniques aiming at the detection and the characterization of polarized signatures. Hereafter, using real observational data, we compare and clarify a number of points concerning various methods of analysis. Indeed, simple line addition, least-squares deconvolution and denoising by principal component analysis have been applied, and compared to each other, to polarized stellar spectra available from the TBLegacy database of the Narval spectropolarimeter. Such a comparison between various approaches of distinct sophistication levels allows us to make a safe choice for the next implementation of on-line post-processing of our unique database for the stellar physics community.

5 pages, 6 figures (accepted A&A; see also http://tblegacy.bagn.obs-mip.fr/)

References in corpus (2)

• Stellar population models in the UV: I. Characterisation of the New Generation Stellar Library
• Zeeman-Doppler Imaging of Late-Type Stars -- The Surface Magnetic Field of II Peg

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