The source of Galactic cosmic rays (with energies up to 1015 eV) remains unclear, although it is widely believed that they originate in the shock waves of expanding supernova remnants. At present the best way to investigate their acceleration and propagation is by observing the γ-rays produced when cosmic rays interact with interstellar gas. Here we report observations of an extended region of very-high-energy (> 1011 eV) γ-ray emission correlated spatially with a complex of giant molecular clouds in the central 200 parsecs of the Milky Way. The hardness of the γ-ray spectrum and the conditions in those molecular clouds indicate that the cosmic rays giving rise to the γ-rays are likely to be protons and nuclei rather than electrons. The energy associated with the cosmic rays could have come from a single supernova explosion around 104 years ago.
Discovery of very-high-energy γ-rays from the Galactic Centre ridge
- F. Aharonian et al. (H.E.S.S. Collaboration)
- Nature 439, 695-698 (2006)
- 2006
Abstract
Auxiliary informations
Figure 1
Fits file for Fig. 1 (upper panel)
Fits file for Fig. 1 (lower panel) – point source subtracted image
Figure 3
H.E.S.S. data points for Figure 3 (solid points – GC region)
Mean energy Flux Flux Error ( - / + )
[TeV] [/TeV cm^2 s] [/TeV cm^2 s]
0.27 5.31e-11 3.87e-11 3.86e-11 0.44 1.89e-11 5.33e-12 5.34e-12 0.71 9.70e-12 1.44e-12 1.44e-12 1.15 3.07e-12 4.44e-13 4.45e-13 1.85 9.76e-13 1.55e-13 1.56e-13 2.98 3.67e-13 6.22e-14 6.27e-14 4.81 1.01e-13 2.71e-14 2.73e-14 7.76 3.60e-14 1.12e-14 1.13e-14 12.51 7.89e-15 3.91e-15 4.01e-15
H.E.S.S. data points for Figure 3 (open points – Sgr B2 region)
Mean energy Flux Flux Error ( - / + )
[TeV] [/TeV cm^2 s] [/TeV cm^2 s]
0.38 1.06e-11 3.41e-12 3.41e-12 0.98 1.76e-12 2.83e-13 2.83e-13 2.55 1.74e-13 3.34e-14 3.36e-14 6.63 1.87e-14 6.07e-15 6.13e-15 17.23 3.60e-15 9.49e-16 1.01e-15
Remarks: Statistical errors only. Systematic error on energy scale estimated at 20%. See paper for details.
