Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Cosmic Flows : Green Bank and Parkes HI observations   The neutral hydrogen properties of 1,822 galaxies are being studied with the
Green Bank 100m and the Parkes 64m telescopes as part of the 'Cosmic Flows'
program. Observed parameters include systemic velocities, profile line widths,
and fluxes. The line width information can be combined with optical and
infrared photometry to obtain distances. The 1,822 HI observations complement
an inventory of archives. All told, HI line width information is available for
almost all of five samples: (i) luminosity-line width correlation calibrators,
(ii) zero-point calibrators for the supernova Ia scale, (iii) a dense local
sample of spiral galaxies with M_{Ks} < -21 within 3,000 km/s, (iv) a sparser
sample of 60 $\mu$m selected galaxies within 6,000 km/s that provides all-sky
coverage of our extended supercluster complex, and (v) an even sparser sample
of flat galaxies, extreme edge-on spirals, extending in a volume out to 12,000
km/s. The HI information for 13,941 galaxies, whether from the archives or
acquired as part of the Cosmic Flows observational program, is uniformly
re-measured and made available through the Extragalactic Distance Database web
site.

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The categories of this paper are: dg-ga
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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: funct-an
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The categories of this paper are: alg-geom
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The categories of this paper are: hep-ex
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The categories of this paper are: bayes-an
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The categories of this paper are: q-alg
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The categories of this paper are: comp-gas
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The categories of this paper are: hep-th
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The categories of this paper are: math
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The categories of this paper are: solv-int
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The categories of this paper are: eess
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The categories of this paper are: supr-con
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The categories of this paper are: q-fin
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The categories of this paper are: cond-mat