Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Some spectral properties of the quasar ultraviolet bump   In the present work the part of the quasar UV-optical bump within the
wavelength range 1210-1450\AA\ was studied with the help of composite spectra
compiled from the samples of SDSS DR7 spectra with the similar spectral index
\alpha_{\lambda} within 1270-1480 \AA. This division allowed to see weak
emission lines, which were not detected in previous studies of the quasar
composite spectra, but were known from individual optical or composite UV
spectra from the Hubble Space Telescope. Although the physical explanation of
the difference in spectral indices between quasars and their dependence on
quasar parameters is still not clear, it is obvious that this difference has to
be taken into account when generating composite spectra, e.g. for redshift
measurements. It was also shown that the equivalent width of the emission lines
does not depend on the spectral index.

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The categories of this paper are: gr-qc
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The categories of this paper are: funct-an
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The categories of this paper are: mtrl-th
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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: chem-ph
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The categories of this paper are: adap-org
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The categories of this paper are: alg-geom
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The categories of this paper are: nucl-ex
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The categories of this paper are: hep-th
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat
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The categories of this paper are: acc-phys
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The categories of this paper are: chao-dyn
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The categories of this paper are: nlin
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The categories of this paper are: cs