Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Resonant Cyclotron Scattering and Comptonization in Neutron Star
  Magnetospheres   Resonant cyclotron scattering of the surface radiation in the magnetospheres
of neutron stars may considerably modify the emergent spectra and impede
efforts to constraint neutron star properties. Resonant cyclotron scattering by
a non-relativistic warm plasma in an inhomogeneous magnetic field has a number
of unusual characteristics: (i) in the limit of high resonant optical depth,
the cyclotron resonant layer is half opaque, in sharp contrast to the case of
non-resonant scattering. (ii) The transmitted flux is on average Compton
up-scattered by ~ $1+ 2 beta_T$, where $\beta_T$ is the typical thermal
velocity in units of the velocity of light; the reflected flux has on average
the initial frequency. (iii) For both the transmitted and reflected fluxes the
dispersion of intensity decreases with increasing optical depth. (iv) The
emergent spectrum is appreciably non-Plankian while narrow spectral features
produced at the surface may be erased.
  We derive semi-analytically modification of the surface Plankian emission due
to multiple scattering between the resonant layers and apply the model to
anomalous X-ray pulsar 1E 1048.1--5937. Our simple model fits just as well as
the ``canonical'' magnetar spectra model of a blackbody plus power-law.

37
The categories of this paper are: supr-con
26
The categories of this paper are: bayes-an
12
The categories of this paper are: nucl-th
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
21
The categories of this paper are: adap-org
8
The categories of this paper are: hep-ex
23
The categories of this paper are: solv-int
10
The categories of this paper are: q-bio
34
The categories of this paper are: chem-ph
30
The categories of this paper are: q-alg
9
The categories of this paper are: nlin
25
The categories of this paper are: patt-sol
1
The categories of this paper are: cs
15
The categories of this paper are: nucl-ex
29
The categories of this paper are: funct-an