Supermassive Black Holes: The Inverse Dinosaur Problem Douglas Richstone University of Michigan

1. Supermassive Black Holes: The Inverse Dinosaur Problem Douglas RichstoneUniversity of Michigan

2. Summary • The ‘inverse dinosaur problem’. • Quasars, observations of test-mass dynamics, interpretation. • The current demographic picture • M- relation, bh mass spectrum, density, comparison to quasars. • Emerging developments – • a theory • Extension to very low masses • spins • Possibility of gravitational wave observation of BH mergers.

3. 3c175

4. Mysterious properties of quasistellar objects • Rapid variability – minutes. • Light travel time across inner solar system. • Directed energy output (collimated beams of high-energy particles. • “Superluminal” motion. • Enormous luminosities ~ 1011 suns. • Objects the size of the solar system that outshine the galaxy. • Quasars were populous in the youthful universe, but are rare now.

5. Quasars and Black Holes • Small size, large luminosity and apparent stability suggest that quasars are gravity powered. • Ultimate gravitational engine is a bh. Some fraction of accreted energy is radiated (can greatly exceed thermonuclear energy). • BH turns off when fuel is cut off. • The decline of Quasars creates the “inverse dinosaur problem” – where are the relics.

6. Inverse dinosaur problem • The light radiated by quasars is proportional to mc2 of accreted matter. • The mass of order m of the accreted matter. • The density of quasars mandates a density of bh of about 2 x 105 solar masses/Mpc3. • Where are the relics?

9. Circular and parabolic orbits

11. M84

14. Orbit Superposition (Schwarzschild’s method) • Assume a mass distribution. • Compute the gravitational forces. • Follow all the orbits. • Sum the orbits to match the observed velocities. • Failure rules out the mass distribution.

19. NGC 4258 • NGC 4258 Maser mass is 3.9 107 at this distance.

21. Results of 15 year effort • Most bulges have BH (97% so far). • BH mass tracks main-body parameters (L, ).

24. Bulge M/L ~ 3x10-3h • Density - 2.5x105 Msun/Mpc-3 for h=.65 (Yu & Tremaine) - 4.8x105h2Msun/Mpc-3 (Aller & Richstone) • consistent results from different datasets. • S = 2.2x105 Msun/Mpc3

25. A note on backgrounds • Any background can be expressed in terms of the cosmic microwave background energy density (about 1eV/cm3). • Backgrounds (other than the CMB) can be seen as integrals of source counts. • uqso ~ 10-4 • bh ~ uqso-1(1 - )(1 - fgw – fejections)

28. Only gas will produce the correct Soltan number • Accreting matter: • Stars • Degenerate objects • Dark matter • Gas

30. Implications • BH growth spurt during quasar era (is this the epoch of bulge formation?). • What is the pedigree of BH and galaxies? • Co-Evolution! --- feeding, bar disruption, core scouring, mergers --- bh growh connected to galaxy evolution. • Is any of this observable?

32. Thermodynamics of the protogalaxy • QSO emits Xrays: 0.1*m.c2 in 108yr • Galaxy has stars: 0.01*Mc2 in 1010yr • QSO light/starlight ~ 103 m./M ~ 1 • bh is as important as stars in early phases of galaxy.

35. LISA sky

37. Grav waves.