Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: X-ray Observations of Galaxies: The Importance of Deep High-Resolution
  Observations   X-ray observations of galaxies have grown from a curiosity into a
full-fledged field of astronomy. These observations provide unique information
on black holes, binary stars, and the hot phase of the ISM, which can be used
to constrain the chemical evolution of the Universe, and the joint evolution of
galaxies and massive black holes. These exciting results are due in large part
to the high-resolution capability of {\it Chandra}. To follow on {\it Chandra}
and push forward this science past the present capabilities, our community must
build a high-resolution (sub-arcsecond) large-area (several square meters)
X-ray telescope.

8
The categories of this paper are: hep-ex
0
The categories of this paper are: hep-ph
1
The categories of this paper are: cs
36
The categories of this paper are: cmp-lg
11
The categories of this paper are: hep-lat
4
The categories of this paper are: cond-mat
17
The categories of this paper are: q-fin
28
The categories of this paper are: alg-geom
33
The categories of this paper are: plasm-ph
23
The categories of this paper are: solv-int
20
The categories of this paper are: acc-phys
2
The categories of this paper are: math
9
The categories of this paper are: nlin
34
The categories of this paper are: chem-ph
16
The categories of this paper are: stat
3
The categories of this paper are: physics