All massive galaxies likely have supermassive black holes at their centers , and the masses of the black holes are known to correlate with properties of the host galaxy bulge component [ 1 ] .
Several explanations have been proposed for the existence of these locally-established empirical relationships ; they include the non-causal , statistical process of galaxy-galaxy merging [ 2 ] , direct feedback between the black hole and its host galaxy [ 3 ] , or galaxy-galaxy merging and the subsequent violent relaxation and dissipation [ 4 ] .
The empirical scaling relations are thus important for distinguishing between various theoretical models of galaxy evolution [ 5 , 6 ] , and they further form the basis for all black hole mass measurements at large distances .
In particular , observations have shown that the mass of the black hole is typically 0.1 % of the stellar bulge mass of the galaxy [ 7 , 8 ] .
The small galaxy NGC 4486B currently has the largest published fraction of its mass in a black hole at 11 per cent [ 9 , 1 ] .
Here we report observations of the stellar kinematics of NGC 1277 , which is a compact , disky galaxy with a mass of 1.2 \times 10 ^ { 11 } M _ { \odot } .
From the data , we determine that the mass of the central black hole is 1.7 \times 10 ^ { 10 } M _ { \odot } , or 59 % its bulge mass .
Five other compact galaxies have properties similar to NGC 1277 and therefore may also contain over-sized black holes .
It is not yet known if these galaxies represent a tail of a distribution , or if disk-dominated galaxies fail to follow the normal black hole mass scaling relations [ 10 , 4 ] .