Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: High energy cosmic rays from AGN and the GZK cutoff   Based on a model for the emission of high energy cosmic rays from AGN (Active
Galactic Nuclei) that has been proposed by the author, he reviews the status of
the GZK cutoff and the correlation of high energy cosmic ray sources with AGN
locations in the existing data. The determination of mass for the incident
particles seems to be a key factor, and a suggestion for doing that has been
made in this article.

27
The categories of this paper are: comp-gas
11
The categories of this paper are: hep-lat
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
10
The categories of this paper are: q-bio
5
The categories of this paper are: gr-qc
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
22
The categories of this paper are: chao-dyn
9
The categories of this paper are: nlin
16
The categories of this paper are: stat
14
The categories of this paper are: math-ph
36
The categories of this paper are: cmp-lg
21
The categories of this paper are: adap-org
26
The categories of this paper are: bayes-an
35
The categories of this paper are: mtrl-th