Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Extragalactic cosmic ray self-confinement around sources   Most models of the origin of ultra high energy cosmic rays rely on the
existence of luminous extragalactic sources. Cosmic rays escaping the galaxy
where the source is located produce a sufficiently large electric current to
justify the investigation of plasma instabilities induced by such current. Most
interesting is the excitation of modes that lead to production of magnetic
perturbations that may scatter particles thereby hindering their escape, or at
least changing the propagation mode of escaping cosmic rays. We argue that
self-generation of waves may force cosmic rays to be confined in the source
proximity for energies $E\lesssim 10^{7} L_{44}^{2/3}$ GeV for low background
magnetic fields ($B_{0}\ll nG$). For larger values of $B_{0}$, cosmic rays are
confined close to their sources for energies $E\lesssim 2\times 10^{8}
\lambda_{10} L_{44}^{1/4} B_{-10}^{1/2}$ GeV, where $B_{-10}$ is the field in
units of $0.1$ nG, $\lambda_{10}$ is its coherence length in units of 10 Mpc
and $L_{44}$ is the source luminosity in units of $10^{44}$ erg/s.

28
The categories of this paper are: alg-geom
19
The categories of this paper are: eess
37
The categories of this paper are: supr-con
32
The categories of this paper are: atom-ph
21
The categories of this paper are: adap-org
0
The categories of this paper are: hep-ph
20
The categories of this paper are: acc-phys
14
The categories of this paper are: math-ph
15
The categories of this paper are: nucl-ex
2
The categories of this paper are: math
3
The categories of this paper are: physics
1
The categories of this paper are: cs
34
The categories of this paper are: chem-ph
23
The categories of this paper are: solv-int
29
The categories of this paper are: funct-an
18
The categories of this paper are: econ