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Magnetized Iron Atmospheres for Neutron Stars

Mohan Rajagopal·Roger W. Romani·M. Coleman Miller
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Abstract

Using a Hartree-Fock formalism, we estimate energy levels and photon cross sections for atomic iron in magnetic fields B ~ 10^13 G. Computing ionization equilibrium and normal mode opacities with these data, we construct LTE neutron star model atmospheres at 5.5 < Log(T_eff) < 6.5 and compute emergent spectra. We examine the dependence of the emergent spectra on T_eff and B. We also show the spectral variation with the angle between the magnetic field and the atmosphere normal and describe the significant limb darkening in the X-ray band. These results are compared with recent detailed computations of neutron star H model atmospheres in high fields and with low field Fe and H model atmospheres constructed from detailed opacities. The large spectral differences for different 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.

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Mohan Rajagopal, Roger W. Romani, M. Coleman Miller. 1996-10-24. Magnetized Iron Atmospheres for Neutron Stars. https://doi.org/10.1086/303865

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