Impact of Future Observations

Caution: IMBH not conclusively established!

What new observations could bear on origin?

Evidence for rotation in globular cores.

Should isotropize in $t_{\rm relax}$, $\sim 10^7$ yr in core.

Needs recent deposit of angular momentum.

IMBH binary? Companion would have to be $10-20\,M_\odot$ black hole.

If observations are confirmed and no other explanation is found:

Establishes current mergers of IMBH.

Can't determine initial mass...

...but guarantees strong GW sources.