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We present a study of the wind launching region of the Herbig Be star HD58647 using high angular (lambda/2B=0.003") and high spectral (R=12000)resolution interferometric VLTI-AMBER observations of the near-infraredhydrogen emission line, Br-gamma. The star displays double peaks in bothBr-gamma line profile and wavelength-dependent visibilities. Thewavelength-dependent differential phases show S-shaped variations around theline centre. The visibility level increases in the line (by ~0.1) at thelongest projected baseline (88 m), indicating that the size of the lineemission region is smaller than the size of the K-band continuum-emittingregion, which is expected to arise near the dust sublimation radius of theaccretion disc. The data have been analysed using radiative transfer models toprobe the geometry, size and physical properties of the wind that is emittingBr-gamma. We find that a model with a small magnetosphere and a disc wind withits inner radius located just outside of the magnetosphere can well reproducethe observed Br-gamma profile, wavelength-dependent visibilities, differentialand closure phases, simultaneously. The mass-accretion and mass-loss ratesadopted for the model are Mdot_a = 3.5 x 10^{-7} Msun/yr and Mdot_dw = 4.5 x10^{-8} Msun/yr, respectively (Mdot_dw/Mdot_a =0.13). Consequently, about 60per cent of the angular momentum loss rate required for a steady accretion withthe measured accretion rate is provide by the disc wind. The smallmagnetosphere in HD 58647 does not contribute to the Br-gamma line emissionsignificantly.

Probing the wind launching regions of the Herbig Be star HD 58647 with high spectral resolution interferometry