Spectroscopy and further imaging of IRAS sources near the Galactic Centre

We present new infrared spectroscopic and imaging observations of IRAS-selected sources suspected of being deeply embedded young stellar objects within 40 pc of the Galactic Centre. These new results are combined with our earlier ones to elucidate further the nature of the sources, with the goal of determining whether star formation has occurred recently in the greater Galactic Centre region. We find that these objects do not form a homogeneous set but can be classified into three groups: (i) compact H ii regions, (ii) pure continuum sources, and (iii) He i or Br$\gamma$ emission-line stars. The latter are probably evolved massive stars. The nature of the pure continuum sources is not clear but their luminosities and their low temperatures, coupled with the fact that at least some of them lie in a tight cluster, suggest that they are very young objects and thus that some stars have been formed near the Centre comparatively recently. The fact that there are objects of different ages in the sample suggests that recent star formation in the Centre has not been in the form of a single burst.