Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Discovery of a Faint Outer Halo Milky Way Star Cluster in the Southern
  Sky   We report the discovery of a new, low luminosity star cluster in the outer
halo of the Milky Way. High quality $gr$ photometry is presented, from which a
color-magnitude diagram is constructed, and estimates of age, [Fe/H],
[$\alpha$/Fe], and distance are derived. The star cluster, which we designate
as Kim 2, lies at a heliocentric distance of $\sim105$ kpc. With a half-light
radius of $\sim12.8$ pc and ellipticity of $\epsilon\sim0.12$, it shares the
properties of outer halo GCs, except for the higher metallicity
([Fe/H]$\sim-1.0$) and lower luminosity ($M_{V}\sim-1.5)$. These parameters are
similar to those for the globular cluster AM 4, that is considered to be
associated with the Sagittarius dwarf spheroidal galaxy. We find evidence of
dynamical mass segregation and the presence of extra-tidal stars that suggests
Kim 2 is most likely a star cluster. Spectroscopic observations for
radial-velocity membership and chemical abundance measurements are needed to
further understand the nature of the object.

14
The categories of this paper are: math-ph
31
The categories of this paper are: ao-sci
24
The categories of this paper are: dg-ga
11
The categories of this paper are: hep-lat
23
The categories of this paper are: solv-int
15
The categories of this paper are: nucl-ex
28
The categories of this paper are: alg-geom
16
The categories of this paper are: stat
3
The categories of this paper are: physics
7
The categories of this paper are: hep-th
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
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The categories of this paper are: comp-gas
36
The categories of this paper are: cmp-lg
2
The categories of this paper are: math
37
The categories of this paper are: supr-con