Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Disk Wind in the Neutron Star Low-mass X-Ray Binary GX 13+1   We present the analysis of seven \emph{Chandra} High Energy Transmission
Grating Spectrometer and six simultaneous \emph{RXTE} Proportional Counter
Array observations of the persistent neutron star (NS) low-mass X-ray binary GX
13+1 on its normal and horizontal branches. Across nearly 10 years, GX 13+1 is
consistently found to be accreting at $50-70$\% Eddington, and all observations
exhibit multiple narrow, blueshifted absorption features, the signature of a
disk wind, despite the association of normal and horizontal branches with jet
activity. A single absorber with standard abundances cannot account for all
seven major disk wind features, indicating that multiple absorption zones may
be present. Two or three absorbers can produce all of the absorption features
at their observed broadened widths and reveal that multiple kinematic
components produce the accretion disk wind signature. Assuming the most ionized
absorber reflects the physical conditions closest to the NS, we estimate a wind
launching radius of $7\times10^{10}$ cm, for an electron density of $10^{12}$
cm$^{-3}$. This is consistent with the Compton radius and also with a thermally
driven wind. Because of the source's high Eddington fraction, radiation
pressure likely facilitates the wind launching.

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The categories of this paper are: physics
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The categories of this paper are: nucl-ex
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The categories of this paper are: ao-sci
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: hep-ex
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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: hep-th
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: chao-dyn
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The categories of this paper are: q-alg
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The categories of this paper are: quant-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: stat