Antoranz Canales, PedroBarrio Uña, Juan AbelContreras González, José LuisFonseca González, María VictoriaLópez Moya, MarcosMiranda Pantoja, José Miguel2023-06-202023-06-202006-05-200004-637X10.1086/504917https://hdl.handle.net/20.500.14352/50931© The American Astronomical Society. We would like to thank the IAC for the excellent working conditions at the Observatory de los Muchachos in La Palma. The support of the German BMBF and MPG, the Italian INFN, and the Spanish CICYT is gratefully acknowledged. This work was also supported by ETH research grant TH 34/04 3 and the Polish MNiI grant 1P03D01028. This Letter is dedicated to the memory of Nicolaj Pavel.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.engjournal articlehttp://dx.doi.org/10.1086/504917http://iopscience.iop.orghttp://arxiv.org/abs/astro-ph/0604197open access537539.4Supernova-RemnantsRay SourcesMilky-WayEmission.Electrónica (Física)ElectricidadFísica nuclear2202.03 Electricidad2207 Física Atómica y Nuclear