Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A study of the cross-correlation and time lag in black hole X-ray binary
  XTE J1859+226   With Rossi X-ray Timing Explorer (RXTE) data, we systematically study the
cross-correlation and time lag in all spectral states of black hole X-ray
binary (BHXB) XTE J1859+226 in detail during its entire 1999-2000 outburst that
lasted for 166 days. Anti-correlations and positive correlations and their
respective soft and hard X-ray lags are only detected in the first 100 days of
the outburst when the luminosity is high. This suggests that the
cross-correlations may be related to high luminosity. Positive correlations are
detected in every state of XTE J1859+226, viz., hard state, hard-intermediate
state (HIMS), soft-intermediate state (SIMS) and soft state. However,
anti-correlations are only detected in HIMS and SIMS, anti-correlated hard lags
are only detected in SIMS, while anti-correlated soft lags are detected in both
HIMS and SIMS. Moreover, the ratio of the observations with anti-correlated
soft lags to hard lags detected in XTE J1859+226 is significantly different
from that in neutron star low-mass X-ray binaries (NS LMXBs). So far,
anti-correlations are never detected in the soft state of BHXBs but detected in
every branch or state of NS LMXBs. This may be due to the origin of soft seed
photons in BHXBs is confined to the accretion disk and, for NS LMXBs, from both
accretion disk and the surface of the NS. We notice that the timescale of
anti-correlated time lags detected in XTE J1859+226 is similar with that of
other BHXBs and NS LMXBs. We suggest that anti-correlated soft lag detected in
BHXB may result from fluctuation in the accretion disk as well as NS LMXB.

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The categories of this paper are: q-fin
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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: quant-ph
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The categories of this paper are: acc-phys
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The categories of this paper are: adap-org
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The categories of this paper are: q-bio
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The categories of this paper are: cmp-lg
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The categories of this paper are: gr-qc
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The categories of this paper are: supr-con
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The categories of this paper are: eess
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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: chao-dyn
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The categories of this paper are: alg-geom
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The categories of this paper are: mtrl-th