Observation of VHE gamma radiation from HESS J1834-087/W41 with the MAGIC telescope

Recently, the HESS array has reported the detection of gamma-ray emission above a few hundred GeV from eight new sources located close to the Galactic plane. The source HESS J1834 - 087 is spatially coincident with the supernova remnant G23.3 - 0.3 (W41). Here we present MAGIC observations of this source, resulting in the detection of a differential gamma-ray flux consistent with a power law, described as dN(gamma)/(dA dt dE) = (3.7 +/- 0.6) x 10(-12) (E/TeV)(-2.5 +/- 0.2) cm(-2) s(-1) TeV-1. We confirm the extended character of this flux. We briefly discuss the observational technique used and the procedure implemented for the data analysis, and we put this detection in the perspective of the molecular environment found in the region of W41. We present (CO)-C-13 and (CO)-C-12 emission maps showing the existence of a massive molecular cloud in spatial superposition with the MAGIC detection.