Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: On the role of galactic magnetic halo in the ultra high energy cosmic
  rays propagation   The study of propagation of Ultra High Energy Cosmic Rays (UHECR) is a key
step in order to unveil the secret of their origin. Up to now it was considered
only the influence of the galactic and the extragalactic magnetic fields. In
this article we focus our analysis on the influence of the magnetic field of
the galaxies standing between possible UHECR sources and us. Our main approach
is to start from the well known galaxy distribution up to 120 Mpc. We use the
most complete galaxy catalog: the LEDA catalog. Inside a sphere of 120 Mpc
around us, we extract 60130 galaxies with known position. In our simulations we
assign a Halo Dipole magnetic Field (HDF) to each galaxy. The code developed is
able to retro-propagate a charged particle from the arrival points of UHECR
data across our galaxies sample. We present simulations in case of Virgo
cluster and show that there is a non negligible deviation in the case of
protons of $7 \times 10^{19}$ eV, even if the $B$ value is conservative. Then
special attention is devoted to the AGASA triplet where we find that NGC3998
and NGC3992 could be possible candidates as sources.

20
The categories of this paper are: acc-phys
31
The categories of this paper are: ao-sci
29
The categories of this paper are: funct-an
10
The categories of this paper are: q-bio
1
The categories of this paper are: cs
23
The categories of this paper are: solv-int
9
The categories of this paper are: nlin
30
The categories of this paper are: q-alg
28
The categories of this paper are: alg-geom
18
The categories of this paper are: econ
12
The categories of this paper are: nucl-th
25
The categories of this paper are: patt-sol
15
The categories of this paper are: nucl-ex
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The categories of this paper are: math-ph
16
The categories of this paper are: stat
4
The categories of this paper are: cond-mat