Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-Parametric Density Reconstruction of the Galactic Bulge Area using
  Red Clump Stars in the VVV Survey   Studies of the red clump giant population in the inner Milky Way suggest the
Galactic bulge/bar has a boxy/peanut/X-shaped structure as predicted by its
formation via a disc buckling instability. We used a non-parametric method of
estimating the Galactic bulge morphology that is based on maximum entropy
regularisation. This enabled us to extract the three-dimensional distribution
of the red giant stars in the bulge from deep photometric catalogues of the
VISTA Variables in the Via Lactea (VVV) survey. Our high-resolution
reconstruction confirms the well-known boxy/peanut/X-shaped structure of the
bulge. We also find spiral arm structures that extend to around three kpc in
front of and behind the bulge and are on different sides of the bulge major
axis. We show that the detection of these structures is robust to the
uncertainties in the luminosity function.

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The categories of this paper are: supr-con
10
The categories of this paper are: q-bio
22
The categories of this paper are: chao-dyn
36
The categories of this paper are: cmp-lg
15
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: patt-sol
29
The categories of this paper are: funct-an
4
The categories of this paper are: cond-mat
24
The categories of this paper are: dg-ga
30
The categories of this paper are: q-alg
33
The categories of this paper are: plasm-ph
9
The categories of this paper are: nlin
35
The categories of this paper are: mtrl-th
18
The categories of this paper are: econ