Black Holes in Universe - From Stellar Masses to Supramassive Objects in Galaxies

1. Black Holes in Universe -From Stellar Masses toSupramassive Objects in Galaxies Max Camenzind Center for Astronomy Heidelberg (ZAH) @ Landessternwarte (2005)

2. Prologue: Chandrasekhar 1983 • „The black holes of nature are the most perfect macroscopic objects there are in the universe: the only elements in their construction are our concepts of space and time. And since the general theory of relativity provides only a single unique family of solutions for their descriptions, they are the simplest objects as well.“ •  No matter is involved in their construction [i.e. no EOS], a Black Hole is a global vacuum solution with horizon, a kind of gravitational soliton. in Chandrasekhar (1983): „The Mathematical Theory of BHs“

3. Topics • The Long History of Black Hole Physics. • The Year 1963 and Kerr Black Hole Gravitational field is not Newtonian ! • Evidence for the Existence of Black Holes  4 Classes of Astrophysical Objects.  „No Hair Plane (Glatzenebene)“ (M,a). • Accretion: New Paradigm of disk accretion onto Black Holes (Balbus & Hawley 1991). • Magnetic Fields - The Spin Paradigm: The Ergosphere as a Source of Energy  Launch Jets (Blandford & Znajek 1977)  still largely not understood. • Beyond Einstein ? Dreams and Future

4. The Long Way towards BHs • 1915: Einstein postulates the field equations (together with Hilbert). • 1916: Schwarzschild Solution Schwarzschild radius RS =2GM/c² = 3 km M / MS • Einstein denied the reality of Black Holes … He considered Black Holes as a mere mathematical curiosity. • This view changed after his death  detection of Quasars (> 1963)  observation of Cygnus X-1 (1971)

5. 1963 – Foundation of Black Holes 1923 - Milestone 1: George Birkhoff: Schwarzschild spacetime geometry is the unique spherically symmetric solution of the Einstein vacuum field equations • 1939 - Robert Oppenheimer & Hartland Snyder show gravitational collapse of a pressureless homogeneous fluid sphere  formation of a trapped region • 1963 – Milestone 2: Roy Kerr solves the Einstein vacuum field equations for uncharged symmetric rotating systems • 1963 – Milestone 3: Quasars are detected  fuelled by accretion onto Black Holes • 1965 - Ezra Newman and collaborators solve the Einstein-Maxwell equations for charged rotating systems • 1967 - Werner Israel presents proof of a "no hair" theorem

6. 1968 – 1977: Golden Age • 1968 – Brandon Carter uses Hamilton-Jacobi theory to derive 1st-order equations of motion for particle moving in Kerr black holes  Kerr Ray-Tracing • 1969 - Roger Penrose discusses the Penrose process for the extraction of the spin energy from a Kerr black hole  Free energy of BHs • 1971 – Milestone 4: Identification of Cygnus X-1/HDE 226868 as a binary black hole candidate system. • 1973 - David Robinson completes the proof of the uniqueness theorem for Kerr black holes • 1977 – Milestone 5: Blandford-Znajek Process  electromagnetic spin energy extraction from rotating black holes

7. 4 Laws of Black Hole Mechanics • 1972 - Stephen Hawking proves that the area of a classical black hole's event horizon cannot decrease. • 1972 - Jacob Bekenstein suggests that black holes have an entropy proportional to their surface area due to information loss effects • 1973 - James Bardeen, Brandon Carter, and Stephen Hawking propose 4 laws of black hole mechanics in analogy with laws of thermodynamics  Free energy • 1973 - Stephen Hawking applies quantum field theory to black hole spacetimes and shows that black holes will radiate particles with a black-body spectrum which can cause black hole evaporation  concept is important, but astrophysically not relevant, and still debated.

8. 1978 – 2005: Observations • 1978 – Sargent et al. show evidence for a supermassive BH in the center of Messier 87 (“serious possibility”). This has been very much debated  but confirmed ! • 1992 – Microquasar GRS 1915+105 found. • 1997 – Fe line redshifts of the innermost portions of accretion disks around rotating supermassive black holes • 2000 - Evidence for the hypothesis that Sagittarius A* is a supermassive black hole at the centre of the Milky Way galaxy • 2002 – The most distant Black Hole found:  Cosmological Redshift z = 6.43 ! (< 1 Gyear old) • 2005 – BHs confirmed in ~ 20 X-Ray Binary Systems ! • 2005 – BHs confirmed in ~ 30 nearby galactic centers ! • 2005 – BHs found in ~ 100,000 Quasars !

9. The Year 1963 and the Physics of Kerr Black Hole

10. How to Treat Gravity of BHs ? In GR the spacetime is a differentiable manifold. The most natural thing is to to foliate it in t=const spatial hypersurfaces St. 1 Measures the “clocks ticking rates” on two St 4 Measures the “stretching” of coordinates 6 Measures distances among points on aSt St unit timelike 4-vector normal to St

11. Spacetime is stationary and axisymmetric • 2 Parameters: • Mass M • Ang. Mom. a • „Charge not • relevant in • Astrophysics“ • Event Horizon rH = M + (M² - a²)1/2

12. Source: Mass Source: Ang. Mom. Also for NSs !

13. Gravity Probe-B will confirm the Existence of Gravitomagnetism

16. 4 Laws of BH Mechanics Bekenstein 1973, Bardeen et al. 1973, Hawking 1974, 1975

19. Extracted by magnetic effects

20. Blandford-Znajek Process Load at infinity J „Split-Monopole“ magnetosphere coupled to rotating Horizon with Znajek Horizon bc drives closed current system  Subject of strong criticism (Punsley) Blandford & Znajek (1977)

21. A Modern Version of BZ Mechanism OLC: Outer Light Surface, compact for Black Holes A: Alfven Surface Plasma injection from near ms orbit; Plasma accretion causal: slow ms, Alfven and fast ms points Proto-Jet wwwww Current Sheet Magnetic fields advected from „Infinity“

22. Twisting of Magnetic Fields • Except for induction terms, evolution of toroidal magnetic field ~ Newtonian MHD •  Source: Differential plasma rotation •  Schwarzschild: no shear ! •  Extreme Kerr: biggest effect ! T ~ RBf Operates outside horizon

23. Black Holes  2 Energy Reservoirs • Potential energy  tapped by accretion  X-rays • Rotational energy  tapped by magnetic fields, similar to rotating neutron stars (Blandford & Znajek 1977)  will feed energy of JETS ! LRot = ERot/tbrake ~ 1046 erg/s (MH/109 MS) (tH/tbrake) LRot = ERot/tbrake ~ 1038 erg/s (MH/10 MS) (tH/tbrake) tbrake = f (a, B,…) [BZ 1977] LBZ = k BH² rH²c (a/M)² (WF[WH-WF]/WH²) ~ MH

24. Anatomy of Black Holes

25. Black Hole Ergosphere Extended Boundary Layer For a > 0.7, radii move inside ergosphere

26. Each form of matterwill be driven to corotationwithin the ergosphere ! Boundary Layer near Horizon ~ rH WH = w(rH) • In Schwarzschild: • No rotation near Horizon !

27. a = 0.5 a = 1.0

28. OutflowsinQuasars & Micro-Quasars ? „StochasticFunnel-Flow“ Conical Outflow Disk Inflow Krolik 2005

29. Field Line Twisting by Rotating Black Holes a = 0 a = 0.5 a = 0.9 a = .998 GRMHD Simulations (Hawley et al. 2005)

30. AstrophysicalBlack Holesin theUniverse

31. Black Holes as Astrophysical Objects • [ Primordial Black Holes: M < 2 MS] • Stellar Black Holes: 2.2 MS < M < 100 MS • Intermediate Mass Black Holes 100 MS < M < 105 MS (?) • Supermassive Black Holes: 105 MS < M < 1010 MS  reside in center of galaxies at all redshifts, 0 < z < 10 (?).

32. 1971 monitored by UHURU • Black Holes are • formed in stellar • Collapse • >100.000 BHs in the Galaxy High-Mass XB Cygnus X-1

33. Cyg X-1 – Activity Cycles (VLA / RXTE) Radio X-Rays HX When high in X-rays  minimum in radio and vice versa  Jet launch

34. Low-MassX-Ray Binaries

35. type of the donor star  type of accretion (wind or Roche lobe overflow) • very different scales: DIFFERENT BINARY SYSTEMS J.A. Orosz Every X-ray binary is a possible microquasar!

36. Stellar Mass Spectrum Clear Separation NSs vs BHs BHs NS

37. X-Ray Emission:VARIABILITY on all Time Scales GX339-4 lightcurve • Variations = changes in the stateof the source • lightcurves: • GX 339-4 / GRS 1915+105 •  Variations on very different time scales ! •  “easy” observations for human time scale 1996 2003 GRS 1915+105 X (2-10 keV) Radio (2,25 GHz) Rau et al (2003)

38. accretion / ejection coupling Mirabel et al (1998) Marscher et al (2002) • cycles of 30 minutes in GRS 1915+105 : • ejections after an X-ray dip • refilling of the internal part of the disc ? • transient ejections during changes of states • same phenomenum in the quasar 3C 120 ?  far slower !

39. GRS 1915+105Microquasar

40. same Lorentz factor as in Quasars :  ~ 5-10 SUPERLUMINAL EJECTIONS VLBI at 22 GHz ~ 1.3 cm VLA at 3.5 cm ~ arcsec. scale ~ milliarcsec. scale Mirabel & Rodriguez (1994) • Move on the sky plane ~103 times faster • Jets are two-sided (allow to solve equations  max. distance)

41. QUASARS  MICROQUASARS Quasar 3C 223 Microquasar 1E1740.7-2942 VLA at 1477MHz ~ 20 cm radio (VLA) observations at 6 cm Mirabel et al. 1992

42. Non-thermal Radio Plasma Black Holes in E-GalaxiesDrive JetsCygnus A (VLA)3C 219 (VLA)  --------- 100 kpc ------------ 

43. A. Müller (LSW) 2004

44. Black Hole Mass ~ Bulge Massfor Inactive Galaxies 30 Nearby Galaxies: MH ~ 0.14% MB Magorrian Relation (N. Häring & H.-W. Rix: ApJL 2004)

45. Mass vs Luminosity of Quasars • LE = 2 x 1031 Watt • x (M/MS) • ~ 5 x 104 LS • maximum • luminosity • minimum mass for BHs

46. Black Hole „Two-Hair Plane“ Microquasars, Stellar BHs, M* > 30 RL Quasars, Radio Galaxies BH s in Galactic Centers and QSOs Intermediate Mass BHs ??? Population III BHs BHs at High Redshifts Neutron Stars

47. Spin a of a Black Hole can bedetermined from Photon Propagation Equations of geodesics integrable Carter Integrals

48. Imageof aRing

49. Line Emission from BH Accretion

50. Schwarzschild Extreme Kerr Extreme Redshift