Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Interpreting the Cosmic Ray Composition   Detailed composition measurements can be a very powerful means of tracing
origins, a fact used regularly by forensic scientists and art historians. One
of the main motivating factors for making detailed observations of cosmic rays
was always the hope that a unique compositional signature could be found which
pointed unambiguously to a particular source. This has proven much harder than
expected, but we have now reached a point where it appears possible to begin to
decipher the information contained in the compositional data; the key, we have
discovered, is to read the data not in isolation, but in the context provided
by our general astronomical knowledge and by recent developments in shock
acceleration theory (Meyer, Drury and Ellison, 1997, 1998; Ellison, Drury and
Meyer, 1997). In our view (not, it is only fair to warn the reader, yet
universally accepted) the data show clearly that the Galactic cosmic ray
particles originate predominantly from the gas and dust of the general
interstellar medium.

31
The categories of this paper are: ao-sci
17
The categories of this paper are: q-fin
11
The categories of this paper are: hep-lat
5
The categories of this paper are: gr-qc
16
The categories of this paper are: stat
27
The categories of this paper are: comp-gas
9
The categories of this paper are: nlin
22
The categories of this paper are: chao-dyn
33
The categories of this paper are: plasm-ph
4
The categories of this paper are: cond-mat
13
The categories of this paper are: quant-ph
3
The categories of this paper are: physics
15
The categories of this paper are: nucl-ex
19
The categories of this paper are: eess
29
The categories of this paper are: funct-an
30
The categories of this paper are: q-alg