Zeeman tomography of magnetic white dwarfs: General method and application to EF Eridani
Abstract
We have developed a new method to derive the magnetic field distribution on the surfaces of rotating magnetic white dwarfs from phase-resolved flux and circular polarization spectra. An optimization code based on an evolutionary strategy is used to fit synthetic Zeeman spectra for a variety of model geometries described in the framework of a truncated multipole expansion. We demonstrate that the code allows the reconstruction of relatively complex fields using noise-added synthetic input spectra. As a first application, we analyze flux and circular polarization spectra of the polar EF Eri in a low state of accretion taken with FORS1 at the ESO VLT.
Cite
@article{arxiv.astro-ph/0303336,
title = {Zeeman tomography of magnetic white dwarfs: General method and application to EF Eridani},
author = {F. Euchner and K. Beuermann and K. Reinsch and S. Jordan and F. V. Hessman and B. T. Gaensicke},
journal= {arXiv preprint arXiv:astro-ph/0303336},
year = {2007}
}
Comments
4 pages, 3 figures, to appear in 'White Dwarfs', proceedings of the 13th European workshop on White Dwarfs, eds. D. de Martino, R. Kalytis, R. Silvotti, J. E. Solheim, in print