1. Cygnus X-1 is a Black Hole Binary

2. Accretion Disks are Efficient
E = mc2
Complete conversion of mass to energy is only possible in matter-antimatter annihilation
But normal accretion disks can convert > 5.7% but < 32% of mass to energy
This is far better than chemical reactions (~ %) or even nuclear fusion (~0.7 %)
Full conversion of 1 M /year = 5.7  1039W

3. Accretion Disks Can Launch Jets
Numerical simulations of jet launching and propagation. (PLATON; Stone)

4. Q4: Quasars Require Tremendous powers: 1039 Watts > 1012 L
Small volumes because of rapid variations
Jet production (frequently)
THEREFORE, the standard model now involves BHs + Accretion Disks
Accretion disks are very compact, with most energy coming out within 20 RS or ~5 light-hours for 108 M BH

5. Evidence for Supermassive Black Holes
NGC 4261: at core of radio emitting jets is a clear disk
~300 lt-yrs across and knot of emission near BH

6. Direct Evidence for Rotating Disk
Masers formed in warped disk in NGC 4258 (and a few other Seyfert galaxies)

7. Supermassive BH at Core of Milky Way
Radio core of Sgr A* is unresolved at 43 GHz, very close to
RS for a 2.6 million solar mass BH “weighed” by orbits of stars measured over a decade in the infrared.

8. Active Galactic Nucleus Model

9. Different AGN from Different Angles
Luminous: Quasars seen close to perpendicular to disk and Ultraluminous Infrared Galaxies near disk plane
Weaker: Type 1 or Type 2 Seyferts
If jets are important:
BL Lacs along jet axis,
Quasars at modest angles & Radio Galaxies at larger angles

10. CONCLUSIONS
Black holes are the natural endpoint of massive star evolution and they have been detected in our galaxy and nearby ones.
Quasars are distant, extremely powerful cores of galaxies.
Accretion disks are efficient and ubiquitous.
Accretion disks around supermassive BHs (106 to 1010 M) are the source of the tremendous powers emitted by quasars and other active galactic nuclei.