Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: The Interstellar Medium of our Galaxy   The development of our understanding of the gaseous component of the
interstellar medium is reviewed. During the 20th century our picture of diffuse
material in space has grown from a simple model of isolated clouds in thermal
equilibrium with stellar radiation fields to one of a richly varied composite
of materials with a wide range of physical properties and morphologies. The
solar system interacts with this dynamical interstellar medium, which dominates
the properties of the interplanetary environment. Optical, radio, and UV
astronomy allow us to study the clouds which form the galactic environment of
the Sun. The composition and distribution of interstellar clouds in the disk
and halo tell us about the history of elemental formation in our galaxy, and
the past and future environment of the solar system.

8
The categories of this paper are: hep-ex
36
The categories of this paper are: cmp-lg
25
The categories of this paper are: patt-sol
17
The categories of this paper are: q-fin
16
The categories of this paper are: stat
31
The categories of this paper are: ao-sci
12
The categories of this paper are: nucl-th
28
The categories of this paper are: alg-geom
13
The categories of this paper are: quant-ph
10
The categories of this paper are: q-bio
15
The categories of this paper are: nucl-ex
7
The categories of this paper are: hep-th
22
The categories of this paper are: chao-dyn
19
The categories of this paper are: eess
30
The categories of this paper are: q-alg
1
The categories of this paper are: cs