1997. The American Astronomical Society. All rights reserved. Printed in U.S.A.( MAGNETIZED IRON ATMOSPHERES FOR NEUTRON STARS

Using a Hartree-Fock formalism, we estimate energy levels and photon cross sections for atomic iron in magnetic Ðelds BD 1013 G. Computing ionization equilibrium and normal mode opacities with these data, we construct LTE neutron star model atmospheres at 5.5 \ log and compute emergent(Teff) \ 6.5spectra. We examine the dependence of the emergent spectra on and B. We also show the spectralTeffvariation with the angle between the magnetic Ðeld and the atmosphere normal and describe the signiÐ-cant limb darkening in the X-ray band. These results are compared with recent detailed computations of neutron star H model atmospheres in high Ðelds and with low-Ðeld Fe and H model atmospheres con-structed from detailed opacities. The large spectral di†erences for di†erent surface compositions may be discernible with present X-ray data; we also note improvements needed to allow comparison of Fe models with high quality spectra