Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Surface Emission Properties of Strongly Magnetic Neutron Stars   We construct radiative equilibrium models for strongly magnetized (B > 10^13
G) neutron-star atmospheres taking into account magnetic free-free absorption
and scattering processes computed for two polarization modes. We include the
effects of vacuum polarization in our calculations. We present temperature
profiles and the angle-, photon energy-, and polarization-dependent emerging
intensity for a range of magnetic field strengths and effective temperatures of
the atmospheres. We find that for B < 10^14 G, the emerging spectra are bluer
than the blackbody corresponding to the effective temperature, T_eff, with
modified Planckian shapes due to the photon-energy dependence of the magnetic
opacities. However, vacuum polarization significantly modifies the spectra for
B~10^15 G, giving rise to power-law tails at high photon energies. The
angle-dependence (beaming) of the emerging intensity has two maxima: a narrow
(pencil) peak at small angles (<5 degrees) with respect to the normal and a
broad maximum (fan beam) at intermediate angles (~20-60 degrees). The relative
importance and the opening angle of the radial beam decreases strongly with
increasing magnetic field strength and decreasing photon energy. We finally
compute a T_eff-T_c relation for our models, where T_c is the local color
temperature of the spectrum emerging from the neutron star surface, and find
that T_c/T_eff ranges between 1.1-1.8. We discuss the implications of our
results for various thermally emitting neutron star models.

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The categories of this paper are: ao-sci
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The categories of this paper are: hep-lat
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: econ
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The categories of this paper are: solv-int
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The categories of this paper are: funct-an
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The categories of this paper are: hep-th
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: q-fin
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The categories of this paper are: mtrl-th
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The categories of this paper are: chao-dyn