Detection of deuterium Balmer lines in the Orion Nebula

摘要

The detection and first identification of the deuterium Balmer emissionlines, D-alpha and D-beta, in the core of the Orion Nebula is reported.Observations were conducted at the 3.6m Canada-France-Hawaii Telescope, usingthe Echelle spectrograph Gecko. These lines are very narrow and have identical11 km/s velocity shifts with respect to H-alpha and H-beta. They are probablyexcited by UV continuum fluorescence from the Lyman (DI) lines and arise fromthe interface between the HII region and the molecular cloud.