Multi-Line Spectro-Polarimetry of Stellar Magnetic Fields Using Principal Components Analysis

Autor(en)

Meir Semel, D. E. Rees, Julio C. Ramirez Velez, Martin Stift, Francesco Leone

Abstrakt

Zeeman-Doppler-Imaging (ZDI) is a technique for the diagnosis of stellar magnetic fields from observations of circularly polarized light, based on the weak-field approximation.

 

This approach has proved adequate in numerous studies of the magnetic fields of solar-type stars. To improve the signal-to-noise ratio, one can add the contributions of different lines to the polarization signature. However, this multi-line extension has been limited by a number of assumptions (e.g., the weak-field approximation). Here we present a novel approach. We created a database of synthetic polarized spectra for different combinations of magnetic-field intensities and orientations. Principal Components Analysis was used to compress the database, so that only few Principal Components are needed to represent all the calculated spectra.

Organisation(en)

Institut für Astrophysik

Externe Organisation(en)

Université Paris VII - Paris-Diderot, Université de recherche Paris Sciences et Lettres, Università degli Studi di Catania

Seiten

355

Publikationsdatum

2006

ÖFOS 2012

1030 Physik, Astronomie

Link zum Portal

https://ucrisportal.univie.ac.at/de/publications/89ba1891-da4a-4a09-88ba-4a6ecd5cba5b