Spins of supermassive black holes in quasars and galaxies
description
Transcript of Spins of supermassive black holes in quasars and galaxies
Spins of supermassive black holes in quasars and galaxies
Jian-Min Wang (王建民 )Institute of High Energy Physics
Chinese Academy of Sciences, Beijing
Dec 1, 2009, ITP
SMBH properties
Physical BHs: mass, spin and charge
Astrophysical SMBHs• Growth: accretion and mergers• Spins: accretion manner, mergers• Formation: high redshift• Duty cycle: activity, coevolution• Obscuration: unification scheme
Outline
• Introduction: quasars and AGNs• Spins 1) Spins: measured from X-rays 2) Spins: measured from -rays 3) spins: cosmological evolution
• Dual AGNs: gravitation wave
• Conclusions • open questions
AGNs and Quasars: Introduction
• Observations: spectra and classifications• Morphology• Theoretical model
Spectral classification
Obscured AGNs by IR observatiosn
NGC 1068
NGC 5548 (AGN) versus NGC 3277 (Normal)
Accretion disks: AGNs and Quasars
Coevolution of SMBH and galaxies
Quasar evolution
Measuring SMBH spins from X-rays
BH accretion disk• Release of Gravitational
energy
• Accretion rates hot corona ADAFs (advection-
dominated accretion flows)
• Geometry of Accretion
Measurements of SMBH spins from X-rays
• Spectral shape• Last stable orbit: radiative efficiency
a*: specific angular momentumSpectral shape + last stable orbit→a*
Reflection of X-rays from cold disk
Line profiles:
affected by the Doppler shifts and gravity
Dependences of profiles on parameters(Fabian et al. 1989; Laor 1990)
• Model parameters: orientation θ emissivity R-β
spins: a*
• a*=0.998, β=0.5
On orientation
On spins
On β
ASCA observation of MCG 6-30-15(Tanaka, et al. 1995, Nature, 375, 659 )
XMM/Newton observations(Fabian et al. 2002, MNRAS, 335, L1)
Suzaku observations (Miniutti et al. 2007, PASJ, 59, S315)
2 Spins of SMBHs from -rays: in M87(Wang et al. 2008, ApJ, 676, L109; Li, Y. et al. 2009, ApJ, 699, 513 )
M87: MBH=3.2 ×109M⊙; D=16Mpc
M87
Conclusions:
1)t ≤ 2 days; 2) Non-beaming effects
GLAST/Fermi observations(Abado et al. 2009, ApJ, 707, 55)
e-rays escaping from the central region
28
e
65.0a
3 Spins: cosmological evolution
QSOgalaxy
QSO
QSOgalaxy
QSO
NNN
ttt
tgalaxy
tQSO
Wang et al. (2006;2008): duty cycle
Soltan (1982); Chokshi & Turner (1992); Yu & Tremaine (2002); Marconi et al. (2004): =0.1
Main growth of SMBH is driven by accretion
Understanding trigger of SMBHs: spins
Spin evolution: -equation(Wang, Hu et al. 2009, ApJ, 697, L141)
SDSSin relation ion reverberat :qso
Properties and advantages:
1) only depends on observables
2) deep survey data for δ: up to redshift z
3) no need to compare with local BH mass density
4) Spin evolution
Bolometric luminosity function and density(Hopkins et al. 2007)
Mass function and BH density(Vestergaard et al. 2008; 2009)
Results
Luminosity density
SMBH density
Vestergaard et al. (2009)
Duty cycle
Hopkins et al. (2007)
Cosmological evolution of SMBH spins
King & Pringle (2007;2008): random accretion
Random accretion: spin-down
MnMMn
ii
1
n
i
n
iii LnLLLL
1
2
1
22 ;
2/12/1
nML
nMLa
Evidence for random accretion• Schmidt (1997), Pringle (1998) jet/disk is randomly-orientated torus is randomly-orientated disk+torus+galaxy have random orientation.
• Munoz Marin (2007)
Numerical simulations(Berti & Volonteri 2008)
Pure mergers Merger+standard accretion Merger+random accretion
What is driving the random accretion onto SMBH?
4 Dual AGNs: gravitational wave(Wang et al. 2009, ApJ, 705, L76)
SDSS: Sloan Digital Sky Survey
• 87 type 2 AGN sample
• Measurements: redshifts
• Properties?
Double peaked [O III] profile:
T. Heckman (1980; 1981)Whittle (1985)
Kepler Relation
Liu, Shen, Strauss et al. (2009, arXiv: 0908:2426)
Kepler relation
Merritt & Ekers (2002)
Conclusions
1) fast spins: in MCG -6-30-15 and M87
2) strong evolution of SMBH spins: spin-down
3) merging galaxies: dual AGNs
Open questions
• X-rays: more detailed and high energy solution• -rays: more observations• Spin evolution: co-evolution of SMBHs and
galaxies• Mergers: major and minor mergers.
Thanks for Attention