Orbit of D2, D23, D3, and D3.1. The Keplerian fit is based on the data presented in Tables D.1 and D.2. The dashed circle indicates the investigated area in the SINFONI data cubes. The Doppler-shifted Brγ line map shows the emission of D2, D23, and D3 (underlined by 50% peak intensity contour lines). In the line map, north is up, east to the left. We do not show the line map of D3.1 since it would dominate the emission of the other sources (for this, consider Fig. 1).