Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Flat radio-spectrum galaxies and BLLacs: Part I: core properties   This paper concerns the relationship of BLLacs and flat spectrum weak
emission-line galaxies. We compare the weak emission-line galaxies and the
BLLacs in a sample of 57 flat spectrum objects (Marcha et al. 1996), using
high-frequency radio and non-thermal optical flux densities, spectral indices
and polarization properties. We consider whether objects which are not
`traditional' BLLacs-due to their larger emission line strengths, and larger
CaII spectral breaks-are simply starlight diluted BLLacs. Their broad-band
spectral properties are consistent with this interpretation, but their radio
polarization may indicate more subtle effects. Comparison of the weak
emission-line galaxies and the BLLacs shows that, on average, the former have
steeper spectra between 8 and 43GHz, and are less polarized at 8.4GHz. This is
consistent with many of the weak-lined objects being at larger angles to the
line of sight than the BLLacs. In addition to this population, we indicate a
number of the weak emission-line galaxies which may be `hidden BLLacs':
relativistically boosted objects very close to the line of sight with an
apparently weak AGN.

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The categories of this paper are: funct-an
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The categories of this paper are: q-alg
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The categories of this paper are: stat
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The categories of this paper are: q-bio
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The categories of this paper are: nucl-ex
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The categories of this paper are: econ
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The categories of this paper are: math
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The categories of this paper are: physics
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The categories of this paper are: cmp-lg
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The categories of this paper are: hep-ph
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The categories of this paper are: chao-dyn
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The categories of this paper are: math-ph
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The categories of this paper are: mtrl-th
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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: cs