Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Next Generation Virgo Cluster Survey. VII. The intrinsic shapes of
  low-luminosity galaxies in the core of the Virgo cluster, and a comparison
  with the Local Group   (Abridged) We investigate the intrinsic shapes of low-luminosity galaxies in
the central 300 kpc of the Virgo cluster using deep imaging obtained as part of
the NGVS. We build a sample of nearly 300 red-sequence cluster members in the
yet unexplored $-14 < M_{g} < -8$ magnitude range. The observed distribution of
apparent axis ratios is then fit by families of triaxial models with
normally-distributed intrinsic ellipticities and triaxialities. We develop a
Bayesian framework to explore the posterior distribution of the model
parameters, which allows us to work directly on discrete data, and to account
for individual, surface brightness-dependent axis ratio uncertainties. For this
population we infer a mean intrinsic ellipticity E=0.43, and a mean triaxiality
T=0.16. This implies that faint Virgo galaxies are best described as a family
of thick, nearly oblate spheroids with mean intrinsic axis ratios 1:0.94:0.57.
We additionally attempt a study of the intrinsic shapes of Local Group
satellites of similar luminosities. For the LG population we infer a slightly
larger mean intrinsic ellipticity E=0.51, and the paucity of objects with round
apparent shapes translates into more triaxial mean shapes, 1:0.76:0.49. We
finally compare the intrinsic shapes of NGVS low-mass galaxies with samples of
more massive quiescent systems, and with field, star-forming galaxies of
similar luminosities. We find that the intrinsic flattening in this
low-luminosity regime is almost independent of the environment in which the
galaxy resides--but there is a hint that objects may be slightly rounder in
denser environments. The comparable flattening distributions of low-luminosity
galaxies that have experienced very different degrees of environmental effects
suggests that internal processes are the main drivers of galaxy structure at
low masses--with external mechanisms playing a secondary role.

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The categories of this paper are: stat
22
The categories of this paper are: chao-dyn
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The categories of this paper are: cmp-lg
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The categories of this paper are: bayes-an
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The categories of this paper are: nlin
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The categories of this paper are: hep-ex
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The categories of this paper are: q-alg
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The categories of this paper are: econ
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The categories of this paper are: atom-ph
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The categories of this paper are: patt-sol
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The categories of this paper are: nucl-ex
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The categories of this paper are: cs
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The categories of this paper are: hep-lat
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The categories of this paper are: dg-ga
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The categories of this paper are: q-bio
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The categories of this paper are: ao-sci