Cygnus X-1 is a Black Hole Binary

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 (~ 0.0001 %) or even nuclear fusion (~0.7 %) Full conversion of 1 M /year = 5.7  1039W

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

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

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

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

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.

Active Galactic Nucleus Model

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

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.