Figure 3: A crude illustration of the parameter space for a SBH-IBH binary at the Galactic center.
Assuming a circular orbit around a SBH of 
, a IBH with mass 
and semi-major
axis 
can be ruled out by measurement of an astrometric wobble of the radio image of Sgr A
.
The shaded regions show the detection thresholds for astrometric resolutions of 
, 
and
milliarcseconds, respectively, assuming a monitoring period of 
years. The dashed lines
indicate coalescence due to gravitational radiation in 
and 
years, respectively (From [84],
see also [229]).