Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Radiative Transfer with Finite Elements II. Ly-alpha Line Transfer in
  Moving Media   A finite element method for solving the resonance line transfer problem in
moving media is presented. The algorithm works in three spatial dimensions on
unstructured grids which are adaptively refined by means of an a posteriori
error indicator. Frequency discretization is implemented via a first-order
Euler scheme. We discuss the resulting matrix structure for coherent isotropic
scattering and complete redistribution. The solution is performed using an
iterative procedure, where monochromatic radiative transfer problems are
successively solved. The present implementation is applicable for arbitrary
model configurations with an optical depth up to 10^(3-4). Results of Ly-alpha
line transfer calculations for a spherically symmetric model, a disk-like
configuration, and a halo containing three source regions are discussed. We
find the characteristic double-peaked Ly-alpha line profile for all models with
an optical depth > 1. In general, the blue peak of the profile is enhanced for
models with infall motion and the red peak for models with outflow motion. Both
velocity fields produce a triangular shape in the two-dimensional Ly-alpha
spectra, whereas rotation creates a shear pattern. Frequency-resolved Ly-alpha
images may help to find the number and position of multiple Ly-alpha sources
located in a single halo. A qualitative comparison with observations of
extended Ly-alpha halos associated with high redshift galaxies shows that even
models with lower hydrogen column densities than required from profile fitting
yield results which reproduce many features in the observed line profiles and
two-dimensional spectra.

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The categories of this paper are: bayes-an
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The categories of this paper are: cs
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The categories of this paper are: atom-ph
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The categories of this paper are: stat
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The categories of this paper are: math-ph
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The categories of this paper are: nlin
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The categories of this paper are: hep-lat
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The categories of this paper are: chem-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom
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The categories of this paper are: eess
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The categories of this paper are: plasm-ph
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The categories of this paper are: chao-dyn