The Hot Core – Ultracompact H Connection in G 10 . 47 + 0 . 03 ⋆

We present infrared imaging and spectroscopic data of the complex massive star-forming region G10.47+0.03. The detection of seven mid-infrared (MIR) sources in our field combined with a sensitive Ks/ISAAC image allows to establish a very accurate astrometry, at the level of 0. ′′ 3. Two MIR sources are found to be coincident with two ultracompact H  regions (UCH s) within our astrometric accuracy. Another MIR source lies very close to three other UCH  regions and to the hot molecular core (HMC) in G10.47+0.03. Spectroscopy of two of the most interesting MIR sources allows to identify the location and spectral type of the ionizing sources. We discuss in detail the relationship between the HMC, the UCH  regions and the nearby MIR source. The nature of the other MIR sources is also investigated.