New constraints on the Mid-IR EBL from the HESS discovery of VHE gamma rays from 1ES 0229+200

Understand

AIMS: To investigate the very high energy (VHE: >100 GeV) gamma-ray emission from the high-frequency peaked BL Lac 1ES 0229+200.

• METHODS: Observations of 1ES 0229+200 at energies above 580 GeV were performed with the High Energy Stereoscopic System (HESS) in 2005 and 2006.
• RESULTS: 1ES 0229+200 is discovered by HESS to be an emitter of VHE photons.
• A signal is detected at the 6.6 sigma level in the HESS observations (41.8 h live time).