Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Line-of-sight velocity distributions of elliptical galaxies from
  collisionless mergers   We analyse the skewness of the line-of-sight velocity distributions in model
elliptical galaxies built through collisionless galaxy mergers. We build the
models using large N-body simulations of mergers between either two spiral or
two elliptical galaxies. Our aim is to investigate whether the observed ranges
of skewness coefficient (h3) and the rotational support (V/sigma), as well as
the anticorrelation between h3 and V, may be reproduced through collisionless
mergers. Previous attempts using N-body simulations failed to reach V/sigma ~
1-2 and corresponding high h3 values, which suggested that gas dynamics and
ensuing star formation might be needed in order to explain the skewness
properties of ellipticals through mergers. Here we show that high V/sigma and
high h3 are reproduced in collisionless spiral-spiral mergers whenever a
central bulge allows the discs to retain some of their original angular
momentum during the merger. We also show that elliptical-elliptical mergers,
unless merging from a high-angular momentum orbit, reproduce the strong
skewness observed in non-rotating, giant, boxy ellipticals. The behaviour of
the h3 coefficient therefore associates rapidly-rotating disky ellipticals to
disc-disc mergers, and associates boxy, slowly-rotating giant ellipticals to
elliptical-elliptical mergers, a framework generally consistent with the
expectations of hierarchical galaxy formation.

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The categories of this paper are: nucl-ex
31
The categories of this paper are: ao-sci
26
The categories of this paper are: bayes-an
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The categories of this paper are: funct-an
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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: eess
3
The categories of this paper are: physics
9
The categories of this paper are: nlin
8
The categories of this paper are: hep-ex
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The categories of this paper are: chao-dyn
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The categories of this paper are: solv-int
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The categories of this paper are: supr-con
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The categories of this paper are: cmp-lg
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The categories of this paper are: econ
4
The categories of this paper are: cond-mat