Discovery of very-high-energy-ray emission from the vicinity of PSR J1913+1011 with H.E.S.S.

The H.E.S.S. experiment, an array of four Imaging Atmospheric Cherenkov Telescopes with high sensitivity and large fiel d-of-view, has been used to search for emitters of very-high-energy (VHE,>100 GeV)γ-rays along the Galactic plane, covering the region 30 ◦ < l < 60 ◦ , 280 ◦ < l < 330 ◦ , and−3 ◦ < b < 3 ◦ . In this continuation of the H.E.S.S. Galactic Plane Scan, a new extended VHEγ-ray source was discovered atα2000=19 h 12 m 49 s ,δ2000=+10 ◦ 09 ′ 06 ′′ (HESS J1912+101). Its integral flux between 1-10 TeV is ∼ 10% of the Crab Nebula flux in the same energy range. The measured energy spectrum can be described by a power law dN/dE ∼ E − with a photon index = 2.7± 0.2stat± 0.3sys. HESS J1912+101 is plausibly associated with the high spin-down luminosity pulsar PSR J1913+1011. We also discuss associations with an as yet unconfirmed SNR candidate proposed from low frequency radio observation and/or with molecular clouds found in 13 CO data.