Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: A Unified Model for the Fan Region and the North Polar Spur: A bundle of
  filaments in the Local Galaxy   We present a simple, unified model that can explain two of the brightest,
large-scale, diffuse, polarized radio features in the sky, the North Polar Spur
(NPS) and the Fan Region, along with several other prominent loops. We suggest
that they are long, magnetized, and parallel filamentary structures that
surround the Local arm and/or Local Bubble, in which the Sun is embedded. We
show this model is consistent with the large number of observational studies on
these regions, and is able to resolve an apparent contradiction in the
literature that suggests the high latitude portion of the NPS is nearby, while
lower latitude portions are more distant. Understanding the contributions of
this local emission is critical to developing a complete model of the Galactic
magnetic field. These very nearby structures also provide context to help
understand similar non-thermal, filamentary structures that are increasingly
being observed with modern radio telescopes.

7
The categories of this paper are: hep-th
25
The categories of this paper are: patt-sol
18
The categories of this paper are: econ
26
The categories of this paper are: bayes-an
36
The categories of this paper are: cmp-lg
19
The categories of this paper are: eess
8
The categories of this paper are: hep-ex
24
The categories of this paper are: dg-ga
15
The categories of this paper are: nucl-ex
3
The categories of this paper are: physics
37
The categories of this paper are: supr-con
9
The categories of this paper are: nlin
13
The categories of this paper are: quant-ph
0
The categories of this paper are: hep-ph
35
The categories of this paper are: mtrl-th
17
The categories of this paper are: q-fin