We summarize recent research results on the radiation mechanism of the Super Massive Black Hole (SMBH) candidate SgrA* and ask the question if there are Intermediate Mass Black Hole (IMBH) candidates in the central stellar cluster. Furthermore we give an update on the most recent high velocity stars in the central arcsecond - that are closest to SgrA*. Here we concentrate on the high velocity star cluster dynamics and on the 4711+ stars with orbital time scales down to 4 years only.