Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Restrictions on the parameters of boundary layer and accretion disk of
  X-ray bursters in the low state   Using ASCA observations of several X-ray bursters in the low spectral state
Lx~1-5x10^{36} erg/s) restrictions on the parameters of the accretion disk and
the boundary layer were obtained. The low state spectra of X-ray bursters
observed with ASCA often can be well described by a power law with photon index
of 1.7--2.2 and are not consistent with significant contribution of the soft
spectral component to the total luminosity. For a blackbody spectrum with
temperature of 0.2--2 keV the upper limits correspond to <10--20% of the total
0.5--10 keV luminosity. On the other hand, theoretical calculations predict
that in the case of a Keplerian accretion disk around a slowly rotating neutron
star (with radius of 3Rg) ~2/3 of the total gravitational energy released in
the system can be released in the boundary layer between the inner part of the
accretion disk and the neutron star surface.
  More accurate analysis of the ASCA spectra shows that:
  (1) The inner radius of the standard geometrically thin optically thick part
of the accretion disk exceeds $R_{in} > 10-25 R_g$.
  (2) The characteristic temperature in the inner part of the accretion flow
including the boundary layer exceeds $\sim$2 keV independently upon the
assumption about the density in the accretion flow. The electron scattering
gives the dominant contribution to the opacity in this region.

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The categories of this paper are: acc-phys
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The categories of this paper are: nlin
1
The categories of this paper are: cs
31
The categories of this paper are: ao-sci
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The categories of this paper are: econ
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The categories of this paper are: plasm-ph
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The categories of this paper are: bayes-an
4
The categories of this paper are: cond-mat
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The categories of this paper are: math-ph
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The categories of this paper are: funct-an
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The categories of this paper are: supr-con
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The categories of this paper are: patt-sol
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The categories of this paper are: chao-dyn
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga