Multiline Zeeman signatures through line addition
- Autor(en)
- Meir Semel, Julio C. Ramirez Velez, Martin Stift
- Abstrakt
Context: To obtain a significant Zeeman signature in the polarised spectra of a magnetic star, we usually ¿add¿ the contributions of numerous spectral lines; the ultimate goal is to recover the spectropolarimetric prints of the magnetic field in these line additions. Aims: Here we want to clarify the meaning of these techniques of line addition; in particular, we try to interpret the meaning of the ¿pseudo-line¿ formed during this process and to find out why and how its Zeeman signature is still meaningful. Methods: We create a synthetic case of line addition and apply well tested standard solar methods routinely used in research on magnetism in the Sun. Results: The results are convincing and the Zeeman signatures well detected; Solar methods are found to be quite efficient for stellar observations. We statistically compare line addition with least-squares deconvolution and demonstrate that they both give very similar results, as a consequence of the special statistical properties of the weights. Conclusions: The Zeeman signatures are unequivocally detected in this multiline approach. We suggest that magnetic field detection is reliable well beyond the weak-field approximation. Linear polarisation in the spectra of solar type stars can be detected when the spectral resolution is sufficiently high.
- Organisation(en)
- Institut für Astrophysik
- Externe Organisation(en)
- Université de recherche Paris Sciences et Lettres
- Journal
- Astronomy & Astrophysics
- Band
- 504
- Seiten
- 1003-1009
- Anzahl der Seiten
- 7
- ISSN
- 0004-6361
- DOI
- https://doi.org/10.1051/0004-6361/200810428
- Publikationsdatum
- 2009
- Peer-reviewed
- Ja
- ÖFOS 2012
- 103003 Astronomie
- Link zum Portal
- https://ucrisportal.univie.ac.at/de/publications/c000ab16-4505-48f0-b7d9-fc83762be412