We gratefully acknowledge support from
the Simons Foundation and member institutions.
Full-text links:

Download:

Current browse context:

astro-ph.SR

Change to browse by:

References & Citations

Bookmark

(what is this?)
CiteULike logo BibSonomy logo Mendeley logo del.icio.us logo Digg logo Reddit logo

Astrophysics > Solar and Stellar Astrophysics

Title: A numerical code for the analysis of magnetic white dwarf spectra that includes field effects on the chemical equilibrium

Abstract: We present a new magnetic-atmosphere model code for obtaining synthetic spectral fluxes of hydrogen-rich magnetic white dwarfs. To date, observed spectra have been analyzed with models that neglect the magnetic field's effects on the atomic populations. In this work, we incorporate state-of-art theory in the evaluation of numerical densities of atoms, free electrons, and ions in local thermodynamical equilibrium under the action of a magnetic field. The energy distribution of atoms is rigorously evaluated for arbitrary field strength. This energy pattern includes going from tightly bound states to metastable or truly bound, highly excited states embedded in the continuum, that is, over the first Landau level. Finite nuclear mass effects and the coupling between the internal atomic structure and the motion of the atom across the magnetic field are also considered. Synthetic fluxes are generated with integrations of numerical solutions of polarized radiative transfer over the visible stellar disk using a spherical t-design method. The atmosphere code is tested with observations from the Sloan Digital Sky Survey for a group of known magnetic white dwarfs. Physical stellar parameters are obtained from least-squares fits to the observed energy distribution and compared with results of previous works. We show that the use of zerofield ionization equilibrium in spectral analyses can lead to underestimated effective temperatures for highly magnetic white dwarfs.
Comments: 14 pages, 11 figures. Accepted for publication in Astronomy & Astrophysics
Subjects: Solar and Stellar Astrophysics (astro-ph.SR)
Cite as: arXiv:2405.06601 [astro-ph.SR]
  (or arXiv:2405.06601v2 [astro-ph.SR] for this version)

Submission history

From: René D. Rohrmann [view email]
[v1] Fri, 10 May 2024 17:03:27 GMT (1702kb,D)
[v2] Fri, 17 May 2024 17:28:52 GMT (1702kb,D)

Link back to: arXiv, form interface, contact.