Spectrum of the dusty sources in the GC in 2008 and 2015. The K-band spectrum between 2.0 μm and 2.4 μm is continuum subtracted. The red solid line marks the HeI and Brγ rest wavelength at 2.0586 μm and 2.1661 μm, respectively. The dashed black lines mark the range of the detected blue and red-shifted emission lines. The green bars represent the range of the detected Doppler-shifted [FeIII] lines. The ³G₅ − ³H₆ and ³G₅ − ³H₅ line are the most prominent of the [FeIII] multiplet. For the purposes of clarity and comprehensibility, the weaker ³G₃ − ³H₄ and ³G₄ − ³H₄ lines are not marked. We only include the spectra of sources that show a line map counterpart in the SINFONI data cubes. Because of the proper motion of the investigated objects and the limited FOV, the observation of the sources is not possible throughout the entire set of SINFONI data cubes between 2005 and 2016. The intensity of the spectrum is in arbitrary units (a.u.).