English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Plus monthly

Global: Zendy Tools annual

Global: Zendy Tools monthly

Global: Zendy Free Plan

We derive the photoionisation cross section in dipole approximation formany-electron atoms and ions for neutron star magnetic field strengths in therange of 10^7 to 10^9 T. Both bound and continuum states are treated inadiabatic approximation in a self-consistent way. Bound states are calculatedby solving the Hartree-Fock-Roothaan equations using finite-element andB-spline techniques while the continuum orbital is calculated by directintegration of the Hartree-Fock equations in the mean-field potential of theremaining bound orbitals. We take into account mass and photon density in theneutron star's atmosphere, finite nuclear mass as well as thermal occupation ofthe levels. The data may be of importance for the quantitative interpretationof observed x-ray spectra that originate from the thermal emission of isolatedneutron stars. They can serve as input for modeling neutron star atmospheres asregards chemical composition, magnetic field strength, temperature, andredshift. Our main focus in this paper lies on helium and helium-like oxygen.These two-electron systems are simple enough to calculate all possibletransitions when limiting the quantum numbers and should show all the basicstructures and behaviour of other two-electron systems up to iron.

Hartree-Fock calculations for the photoionisation of helium and helium-like ions in neutron star magnetic fields