Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The line-of-sight velocity distributions of intracluster planetary
  nebulae in the Virgo cluster core   Radial velocities of 40 intracluster planetary nebulae (ICPNe) in the Virgo
cluster were obtained with the new multi-fiber FLAMES spectrograph on UT2 at
VLT. For the first time, the lambda 4959 AA line of the [OIII] doublet is seen
in a large fraction (50%) of ICPNe spectra, and a large fraction of the
photometric candidates with m(5007) <\= 27.2 is spectroscopically confirmed.
ICPNe with the velocity dispersion of the Virgo cluster are found in our CORE
field 1 deg from M87. These may have originated from tidal mass loss of smaller
galaxies in the M87 subcluster halo. In a field 0.25 deg from M87, we see an
extended stellar halo of M87 in approximate dynamical equilibrium, but with few
ICPNe. Finally, in a field near M84/M86, the ICPNe velocities are highly
correlated with the galaxy velocities, showing that any well-mixed intracluster
population is yet to form. Overall, the measured velocity distributions confirm
the non-uniform dynamical structure and on-going assembly of the Virgo
cluster.(Based on data collected with the FLAMES spectrograph at the UT2 of the
VLT at Cerro Paranal, Chile, operated by ESO, during observing run
71.B-0147(A))

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The categories of this paper are: q-alg
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The categories of this paper are: ao-sci
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The categories of this paper are: physics
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The categories of this paper are: cond-mat
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The categories of this paper are: hep-ex
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The categories of this paper are: dg-ga
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The categories of this paper are: nlin
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The categories of this paper are: plasm-ph
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The categories of this paper are: cs
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The categories of this paper are: bayes-an
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The categories of this paper are: quant-ph
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The categories of this paper are: hep-th
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The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: patt-sol
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The categories of this paper are: hep-lat