AMBER/VLTI high spectral resolution observations of the Brγ emitting region in HD 98922. A compact disc wind launched from the inner disc region

Context. High angular and spectral resolution observations can provide us with fundamental clues to the complex circumstellar structure of young stellar objects (YSOs) and to the physical processes taking place close to these sources. Aims. We analyse the main physical parameters and the circumstellar environment of the young Herbig Be star HD 98922. Methods. We present AMBER/VLTI high spectral resolution (R = 12 000) interferometric observations across the Brγ line, accompanied by UVES high-resolution spectroscopy and SINFONI-AO assisted near-infrared (NIR) integral field spectroscopic data. To interpret our observations, we develop a magneto-centrifugally driven disc-wind model. Results. Our analysis of the UVES spectrum shows that HD 98922 is a young (∼5 × 10 5 yr) Herbig Be star (SpT = B9V), located at a distance of 440± 60 pc, with a mass accretion rate ( u ( �� )( ( ◦ )