Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Relationship Between Luminosity and Broad-Line Region Size in Active
  Galactic Nuclei   We reinvestigate the relationship between the characteristic broad-line
region size (R_blr) and the Balmer emission-line, X-ray, UV, and optical
continuum luminosities. Our study makes use of the best available
determinations of R_blr for a large number of active galactic nuclei (AGNs)
from Peterson et al. Using their determinations of R_blr for a large sample of
AGNs and two different regression methods, we investigate the robustness of our
correlation results as a function of data sub-sample and regression technique.
Though small systematic differences were found depending on the method of
analysis, our results are generally consistent. Assuming a power-law relation
R_blr \propto L^\alpha, we find the mean best-fitting \alpha is about
0.67+/-0.05 for the optical continuum and the broad H\beta luminosity, about
0.56+/-0.05 for the UV continuum luminosity, and about 0.70+/-0.14 for the
X-ray luminosity. We also find an intrinsic scatter of about 40% in these
relations. The disagreement of our results with the theoretical expected slope
of 0.5 indicates that the simple assumption of all AGNs having on average same
ionization parameter, BLR density, column density, and ionizing spectral energy
distribution, is not valid and there is likely some evolution of a few of these
characteristics along the luminosity scale.

20
The categories of this paper are: acc-phys
15
The categories of this paper are: nucl-ex
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The categories of this paper are: chao-dyn
18
The categories of this paper are: econ
29
The categories of this paper are: funct-an
13
The categories of this paper are: quant-ph
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The categories of this paper are: q-fin
25
The categories of this paper are: patt-sol
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The categories of this paper are: hep-th
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The categories of this paper are: dg-ga
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The categories of this paper are: stat
8
The categories of this paper are: hep-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: q-bio
12
The categories of this paper are: nucl-th
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The categories of this paper are: hep-lat