Fermi Gamma-ray Space Telescope

H.E.S.S. Observations of the Large Magellanic Cloud

Nukri Komin
Nukri Komin, Chia-Chun Lu, Stefan Ohm, Michael Mayer and Jacco Vink for the H.E.S.S. Collaboration


The Large Magellanic Cloud (LMC) is an irregular satellite galaxy of the Milky Way. Located at a distance of 50 kpc it is seen nearly face on. In the recent years it has been observed extensively in gamma rays with the Fermi and H.E.S.S. telescopes. On one hand, Fermi/LAT detected large-scale diffuse emission at energies between 200 MeV and 20 GeV. This emission most likely reflects the Cosmic Ray content in the LMC. No individual sources have been identified. On the other hand, H.E.S.S. detected very-high energy (VHE) gamma-ray emission between 600 GeV and 12 TeV from the pulsar wind nebula (PWN) N 157B, which is powered by the Crab-like pulsar PSR J0537-6910. This emission was interpreted as Inverse Compton up-scattering of low-energy photons by relativistic electrons accelerated in the PWN. H.E.S.S., with its superior angular resolution of about 0.05 degrees, can separate individual sources in the LMC. In this talk we will present the result of 210 h observations with the H.E.S.S. telescopes. Besides the already known PWN N 157B, these observations establish significant VHE gamma-ray emission from the superbubble 30 Dor C and show evidence for emission from the supernova remnant (SNR) N 132D. Contrary to theoretical expectations, VHE gamma-ray emission is not detected from SN 1987A. We will discuss these three objects as possible Cosmic Ray accelerators. For the first time, individual Cosmic Ray accelerators are identified in an external galaxy. The properties of the sources will be compared with those of their Galactic counterparts. These discovered objects represent the tip of the VHE gamma-ray source population in the LMC. Further source discoveries can be expected with more sensitive surveys of the LMC in gamma rays, for instance with CTA as the next generation of Cherenkov telescopes.