• Merging black holes give insight into merger tree vs. redshift.
• X-rays can see accreting black holes even for A_V=100.
• Gen-X can detect and resolve a binary AGN 2kpc apart at z=1.
• Angular resolving power increases at the highest redshifts and 0.1" resolution corresponds to physical scales of:
  • 0.8 kpc at z=3
  • 0.6 kpc at z=6
  • 0.3 kpc at z=15
• Hundreds of binary BH systems will be observable with separation of ~1 kpc

Drives Effective area=50 m², Angular Resolution=0.1", Resolving power=10³-10⁴