Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Detection of diffuse gamma-ray emission near the young massive cluster
  NGC 3603   We report the Fermi Large Area Telescope's detection of extended gamma-ray
emission towards the direction of the young massive star cluster NGC 3603. The
emission shows a hard spectrum with a photon index of 2.3 from 1 GeV to 250
GeV. The large size and high luminosity of this structure make it unlikely a
pulsar wind nebular. On the other hand the spatial correlation with the ionised
gas indicate a hadronic origin. The total cosmic ray (CR) protons energy are
estimated to be of the order $10^{50} ~\rm erg$ assuming the gamma-ray are
produced in the interaction of CRs with ambient gas . The environment and
spectral features show significant similarity with the Cygnus cocoon. It
reveals that the young star clusters may be a gamma-ray source population and
they can potentially accelerate a significant fraction of the Galactic cosmic
rays.

14
The categories of this paper are: math-ph
23
The categories of this paper are: solv-int
3
The categories of this paper are: physics
4
The categories of this paper are: cond-mat
34
The categories of this paper are: chem-ph
28
The categories of this paper are: alg-geom
0
The categories of this paper are: hep-ph
24
The categories of this paper are: dg-ga
31
The categories of this paper are: ao-sci
5
The categories of this paper are: gr-qc
13
The categories of this paper are: quant-ph
35
The categories of this paper are: mtrl-th
20
The categories of this paper are: acc-phys
27
The categories of this paper are: comp-gas
37
The categories of this paper are: supr-con
2
The categories of this paper are: math