Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Steps toward Determination of the Size and Structure of the Broad-Line
  Region in Active Galactic Nuclei. XII. Ground-Based Monitoring of 3C 390.3   Results of a ground-based optical monitoring campaign on 3C 390.3 in 1994-95
are presented. The broad-band fluxes (B, V, R, and I), the spectrophotometric
optical continuum flux F(5177) and the integrated emission-line fluxes of Ha,
Hb, Hg, HeI, and HeII all show a nearly monotonic increase with episodes of
milder short-term variations superposed. The amplitude of the continuum
variations increases with decreasing wavelength (4400-9000 A). The optical
continuum variations follow the variations in the ultraviolet and X-ray with
time delays, measured from the centroids of the cross- correlation functions,
typically around 5 days, but with uncertainties also typically around 5 days;
zero time delay between the high-energy and low-energy continuum variations
cannot be ruled out. The strong optical emission lines Ha, Hb, Hg, and HeI
respond to the high-energy continuum variations with time delays typically
about 20 days, with uncertainties of about 8 days. There is some evidence that
HeII responds somewhat more rapidly, with a time delay of around 10 days, but
again, the uncertainties are quite large (~8 days). The mean and rms spectra of
the Ha and Hb line profiles provide indications for the existence of at least
three distinct components located at +-4000 and 0 km/s relative to the line
peak. The emission-line profile variations are largest near line center.

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The categories of this paper are: quant-ph
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The categories of this paper are: nlin
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The categories of this paper are: nucl-ex
1
The categories of this paper are: cs
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The categories of this paper are: dg-ga
33
The categories of this paper are: plasm-ph
0
The categories of this paper are: hep-ph
22
The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: mtrl-th
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The categories of this paper are: acc-phys
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The categories of this paper are: patt-sol
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The categories of this paper are: comp-gas
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The categories of this paper are: q-bio
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The categories of this paper are: physics
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The categories of this paper are: atom-ph