Very high energy gamma rays from the composite SNR G0.9+0.1

Very high energy (>100 GeV) gamma-ray emission has been detected for the first time from the composite supernova remnant G 0.9+0.1 using the HESS$\,$ instrument. The source is detected with a significance of $\approx$$13\sigma$, and a photon flux above 200 GeV of ( $5.7\pm0.7_{\rm stat}\pm1.2_{\rm sys})\times10^{-12}$ cm-2 s-1, making it one of the weakest sources ever detected at TeV energies. The photon spectrum is compatible with a power law ( ${\rm d}N/{\rm d}E \propto E^{-\Gamma}$) with photon index $\Gamma = 2.40\pm0.11_{\rm stat}\pm0.20_{\rm sys}$. The gamma-ray emission appears to originate in the plerionic core of the remnant, rather than the shell, and can be plausibly explained as inverse Compton scattering of relativistic electrons.