Determining the Spin of Supermassive Kerr Black Holes as AGN Central Engines

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  • 1. DDeetteerrmmiinniinngg tthhee SSppiinn ooff SSuuppeerrmmaassssiivvee KKeerrrr BBllaacckk HHoolleess aass AAGGNN CCeennttrraall EEnnggiinneess HHeerrmmaann JJ.. MMoossqquueerraa CCuueessttaa ((IICCRRAANNeett//IIttaallyy -- IICCRRAA//BBrraazziill) AAnnddeerrssoonn CCaapprroonnii ((UUNNIICCSSUULL//BBrraazziill) ZZuulleemmaa AAbbrraahhaamm ((IIAAGG--UUSSPP//BBrraazziill)
  • 2. • Rotating BH drags the spacetime around it (LLeennssee –– TThhiirrrriinngg 11991188). • Particle in an orbit with an axis non-parallel to the spin of the BH will experience torques • The orbit will precess Kerr BH + Particle Precession
  • 3. BBaarrddeeeenn –– PPeetttteerrssoonn ((11997755) Kerr BH + Disk Alignment + Viscosity
  • 4. How can it be observed? From tthhee sshhaappee ooff tthhee aaccccrreettiioonn ddiisskk Warped disk RBP
  • 5. How can it be observed? FFrroomm tthhee PPrreecceessssiioonn ooff ppcc ssccaallee jjeettss Right Ascension (02h 40m) Radio Jet (pc) S2 NE Warped disk RBP Declination (-00o 13') 07s.4 07s.0 30" 35" C S1 Right Ascension Offset (arcsec) 0.8 0.4 0.2 0.0 -0.2 -0.4 0.4 0.2 0.0 06s.6
  • 6. How can it be observed? FFrroomm tthhee ssttrruuccttuurree ooff tthhee rraaddiiooggaallaaxxyy iinn kkppcc ssccaalleess
  • 7. Large scale Radio Structure (kpc) Radio Jet (pc) Warped disk RBP
  • 8. JJeett pprreecceessssiioonn iinn ppcc ssccaalleess How do we observe them 1 pc 1 mas VLBI: Very Long Baseline Interferometry 1.4 GHz
  • 9. VLBI
  • 10. 3C279 superluminal velocities 1992 1994 1996 1998 light years 20 40 60 80
  • 11. 3C273 Jets are wiggled
  • 12. Angle with the line of sight is different Velocity of each component is constant Velocity is different for the different components Position angle in the plane of the sky of each component is different
  • 13. We find a sistematic effect in bobs vs. h, sugesting precession precessão x observer jet W f h y (Abraham & Romero (1999) plane of the sky line of sight γ= 1 √1−β2 b b sin f =  = 3.9o f0 app - b f 1 cos = 10o h0 = -120 g= 10.8 
  • 14. 13 11 9 7 5 3 1960 1965 1970 1975 1980 1985 1990 1995 2000 Time bobs C2 C4 C5 C6 C7 C8 C9 C3 C10 -50 -70 -90 -110 -130 -150 -170 C9 1960 1965 1970 1975 1980 1985 1990 1995 2000 Time h (deg) C2 C3 C4 C5 C6 C7 C8 C10 P = 16 years
  • 15. Precession ooff QQSSOO JJeettss aatt kkppcc SSccaalleess
  • 16. Precession model using the Bardeen-Peterson effect
  • 17. Locus of Pprec/MBH = constant 3C345 3C279 BH spin (a *) log (RBP/Rms) 3C273 OJ287 3C120 (Caproni, Mosquera Cuesta & Abraham, 2004, ApJ, 616, L99)
  • 18. Precession from a BH binary system (Abraham & Romero 1999)
  • 19. Locus of Pprec/MBH = Constant 3C345 BH spin (a *) log (RBP/Rms) 3C273 3C279 OJ287 3C120
  • 20. RBP is too small to be measured with current ang. resolution !! SShhaappee ooff tthhee aaccccrreettiioonn ddiisskk Keplerian outer disk Rigid body Warped disk RBP
  • 21. NGC 1068 7 ´ 6 arc min Optical image (1.1 m Hall telescope) 30 arc sec HST
  • 22. 1 kpc HST VLA Wilson & Ulvestad 1987
  • 23. NGC 1068: Seyfert 2 Gallimore et al.(2004) VLBA 1.4 GHz core counter jet 100 pc 2 pc VLBA 5 GHz masers H2O free-free continnum
  • 24. Lodato & Bertin, A&A 398, 517 (2003)
  • 25. Initial jet direction MBN = (0.8 – 1.2) ´ 107 MMd = (8.6 – 9.4) ´ 106 M S= (1.1 – 1.5) ´ 106 g cm-2 0 Σd (ξ )=Σ0 ξs s = 1 Rex = 1 pc How long does it take to get aligned? What is the value of RBP
  • 26. Talign = < 1.5 ´ 105 Y Alignment Time should be smaller than Lifetime of the AGN and Jet Phases ~ (1-2)*10^5 years
  • 27. (derived from the movement of the components close to the core) NGC 1068 in kpcscales: Wilson & Ulvestad (1987) 1 kpc υjet=0.17c Jet was formed 104 years ago
  • 28. dJ BN dt =−2πsinϕ∫ΩLT Ld (r )rdr ϕ(t )=ϕ0e ( t−t0)/Tali} Sheuer & Feiler (1996) (t−t0 )/T ali Pprec (t )=P0 e P0≃T alin
  • 29. The way to infer the KBH Radius: Combining info from: RBP vs. a* and Talign vs. a*
  • 30. The End