Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Host Galaxy and the Environment of the z = 1.195 Quasar 3C 190   We present deep imaging and spectroscopic observations of the z = 1.195
quasar 3C 190 and its immediate environment. The quasar is surrounded by an
asymmetric low-surface-brightness envelope in which there are also several
galaxies with characteristic dimensions of 3-5 kpc. Some of these form a linear
structure some 50 kpc long in projection, offset from the quasar and almost
perpendicular to the radio axis. Spectroscopy of this feature indicates the
presence of a starburst component as well as stars a few 10^8 years old.
Velocities of the emission- line gas associated with H II regions in the linear
feature are difficult to reconcile with any reasonable model that is also
consistent with the observed morphology. One possible scenario is an edge-on
disk in an extremely massive (~10^12 solar mass) halo; another is two
independent chain galaxies, with the apparent alignment being fortuitous.
Taking into account all of the types of extended material we find in the
vicinity of 3C 190, we appear to be witnessing a relatively brief phase in the
development of a spheroidal galaxy, in which merging is proceeding nearly
simultaneously in a variety of different regimes. This system may be one of the
clearest examples yet found for the mechanism by which many elliptical galaxies
and bulges of early-type spirals form in the early Universe.

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The categories of this paper are: q-bio
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The categories of this paper are: solv-int
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The categories of this paper are: hep-ex
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The categories of this paper are: comp-gas
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The categories of this paper are: physics
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The categories of this paper are: math-ph
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The categories of this paper are: supr-con
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The categories of this paper are: gr-qc
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The categories of this paper are: bayes-an
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The categories of this paper are: cond-mat
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The categories of this paper are: q-fin
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The categories of this paper are: hep-ph
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The categories of this paper are: alg-geom
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The categories of this paper are: cmp-lg
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The categories of this paper are: ao-sci
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The categories of this paper are: mtrl-th