Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Truncation of the Inner Accretion Disk around a Black Hole at Low
  Luminosity   Most black hole binaries show large changes in X-ray luminosity caused
primarily by variations in mass accretion rate. An important question for
understanding black hole accretion and jet production is whether the inner edge
of the accretion disk recedes at low accretion rate. Measurements of the
location of the inner edge (Rin) can be made using iron emission lines that
arise due to fluorescence of iron in the disk, and these indicate that Rin is
very close to the black hole at high and moderate luminosities (near 1% of the
Eddington luminosity, Ledd). Here, we report on X-ray observations of the black
hole GX 339-4 in the hard state by Suzaku and the Rossi X-ray Timing Explorer
(RXTE) that extend iron line studies to 0.14% Ledd and show that Rin increases
by a factor of >27 over the value found when GX 339-4 was bright. The exact
value of Rin depends on the inclination of the inner disk (i), and we derive
90% confidence limits of Rin > 35 Rg at i = 0 degrees and Rin > 175 Rg at i =
30 degrees. This provides direct evidence that the inner portion of the disk is
not present at low luminosity, allowing for the possibility that the inner disk
is replaced by advection- or magnetically-dominated accretion flows.

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The categories of this paper are: ao-sci
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The categories of this paper are: bayes-an
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The categories of this paper are: chem-ph
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The categories of this paper are: cmp-lg
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The categories of this paper are: math-ph
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The categories of this paper are: q-bio
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The categories of this paper are: nlin
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The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-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-lat
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The categories of this paper are: gr-qc
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The categories of this paper are: hep-th