Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Non-thermal radio emission from colliding-wind binaries: modelling Cyg
  OB2 No. 8A and No. 9   Some OB stars show variable non-thermal radio emission. The non-thermal
emission is due to synchrotron radiation that is emitted by electrons
accelerated to high energies. The electron acceleration occurs at strong shocks
created by the collision of radiatively-driven stellar winds in binary systems.
Here we present results of our modelling of two colliding wind systems: Cyg OB2
No. 8A and Cyg OB2 No. 9.

2
The categories of this paper are: math
31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
30
The categories of this paper are: q-alg
10
The categories of this paper are: q-bio
32
The categories of this paper are: atom-ph
19
The categories of this paper are: eess
11
The categories of this paper are: hep-lat
24
The categories of this paper are: dg-ga
27
The categories of this paper are: comp-gas
13
The categories of this paper are: quant-ph
34
The categories of this paper are: chem-ph
37
The categories of this paper are: supr-con
29
The categories of this paper are: funct-an
23
The categories of this paper are: solv-int
33
The categories of this paper are: plasm-ph