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Paper: |
Zeeman Component Decomposition (ZCD): Common Line Profile and Magnetic Field Reconstruction from Polarized Spectra |
Volume: |
437, Solar Polarization Workshop 6 |
Page: |
173 |
Authors: |
Sennhauser, C.; Berdyugina, S. V. |
Abstract: |
We present our new method Zeeman Component Decomposition (ZCD) for recovering an intrinsic line profile and the magnetic field vector from polarized spectra (Sennhauser & Berdyugina 2010b). The ZCD combines advantages of inversion procedures with multi-line techniques (MLT), which is a standard tool in stellar astronomy for increasing the signal-to-noise ratio (SNR) of spectropolarimetric measurements.
In addition to accounting for the nonlinearity in blended profiles (cf. NDD, Sennhauser et al. 2009), ZCD is not restricted by the weak line approximation (WLA), and is independent of pre-calculated line lists. Furthermore, the ZCD overcomes a common disadvantage of MLTs where the weak field approximation (WFA) is widely used. Therefore, the ZCD permits us to analyze many lines with arbitrary Zeeman splitting and to simultaneously deploy Stokes IQUV spectra to determine a common line profile. With all these abilities, ZCD has significantly increased the interpretability of common absorption line profiles, and has at the same time lowered the detection limit for weak magnetic fields. This enabled us for the first time to directly detect a weak longitudinal magnetic field on the surface of the red giant Arcturus. |
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