Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Gamma-Ray Astrophysics   High-energy photons are a powerful probe for astrophysics and for fundamental
physics in extreme conditions. During the recent years, our knowledge of the
most violent phenomena in the Universe has impressively progressed thanks to
the advent of new detectors for gamma rays, both at ground and on satellites.
This article reviews the present status of high-energy gamma-ray astrophysics,
with emphasis on the recent results and a look to the future.

26
The categories of this paper are: bayes-an
11
The categories of this paper are: hep-lat
9
The categories of this paper are: nlin
7
The categories of this paper are: hep-th
32
The categories of this paper are: atom-ph
2
The categories of this paper are: math
14
The categories of this paper are: math-ph
13
The categories of this paper are: quant-ph
19
The categories of this paper are: eess
20
The categories of this paper are: acc-phys
34
The categories of this paper are: chem-ph
31
The categories of this paper are: ao-sci
8
The categories of this paper are: hep-ex
28
The categories of this paper are: alg-geom
4
The categories of this paper are: cond-mat
27
The categories of this paper are: comp-gas