First Steps Toward Constraining Supermassive BlackHole Growth

1
First Steps Toward Constraining Supermassive
Black-Hole Growth
Marianne Vestergaard University of Arizona
Collaborators Misty Bentz, Xiaohui Fan, Shai
Kaspi, Dan Maoz, Hagai Netzer, Chris
Onken, Pat Osmer, Brad Peterson, Rick Pogge,
Adam Steed, David Weinberg
Copenhagen September 9 2005
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Points to Take Away

• MBH in Active Nuclei can be determined to within
  an accuracy
• Low-z factor of 3 (measured)
• Higher z factor of 4 (estimated!!)
• MBH 109 M?, even at 4 ? z ? 6
• Ceilings in LBOL and MBH values
• Mass Functions

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Overview

• What is a quasar?
• Why estimate QSO black-hole masses, MBH ?
• How can we determine MBH
• at low redshift?
• at high redshift?
• Quasar mass distributions at high redshift
• Follow up work

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Active Galactic Nuclei

• A few percent of bright galaxies have an active
  nucleus, an apparently point-like source of
  radiation that is not due to stars.
• The brightest of these are called quasars.

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(Elvis et al. 1994)
10 17 cm
(Francis et al. 1991)
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Why Measure Quasar Black-Hole Masses?

• Probe of quasar central engine
• Quasar evolution ( accretion history)
• Black hole growth
• Cosmological implications for structure formation
  
• Galaxy formation and evolution
• BH/star-formation feedback

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How Can We Measure Black-Hole Masses?

• Virial mass measurements based on motions of
  stars and gas in nucleus.
• Stars
• Advantage gravitational forces only
• Disadvantage requires high spatial resolution
• Gas
• Advantage can be found very close to nucleus
• Disadvantage possible role of non-gravitational
  forces

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Possible Virial Estimators
Mass estimates from the virial theorem M f (r
?V 2 /G) where r scale length of
region ?V velocity dispersion f a factor
of order unity, depends on
details of geometry and kinematics

In units of the Schwarzschild radius RS 2GM/c2
3 1013 M8 cm .
Note the reverberation technique is independent
of angular resolution
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How Can AGN MBH be Determined?
Local Universe
Higher-z

• (v) ?
• (v) ?
• v v

• Stellar kinematics
• Gas kinematics
• Reverberation mapping

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Secondary Mass Estimators
Best Accu- racy
Low-z High-z
Low-L High-L High-L
Liners, Sy2 QSOs, Sy1 QSOs
BL Lacs
(dex)

• Scaling Relations
• Via MBH - ?bulge
• ?bulge
• OIII FWHM
• Fundamental Plane ?e, re
• Via MBH Lbulge scaling rel.
• MR

• v v v
  0.5-0.6
• v v ?
  0.3
• v v v
  0.7
• v v ?
  ?
• v v ?
  0.6-0.7

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Virial Mass Estimates

• MBH f v2 RBLR/G
• Reverberation Mapping RBLRct, vBLR
• Radius Luminosity Relation
  
  (Kaspi et al. 2005 Bentz et al. 2005,
  in prep)
• Scaling Relationships
• MBH ? FWHM2 L ß

RBLR ? L?(5100Å)0.50 RBLR ? L(Hß)0.63 RBLR
? L?(1350Å)0.53
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Velocity Dispersion of the BLR and the Virial Mass

• Velocity dispersion is measured from the line in
  the rms spectrum.
• The rms spectrum isolates the variable part of
  the lines.
• Constant components (like narrow lines) vanish in
  rms spectrum

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Virial Mass Estimates

• MBH f v2 RBLR/G
• Reverberation Mapping RBLRct, vBLR
• Radius Luminosity Relation
  
  (Kaspi et al. 2005 Bentz et al. 2005,
  in prep)
• Scaling Relationships
• MBH ? FWHM2 L ß

RBLR ? L?(5100Å)0.50 RBLR ? L(Hß)0.63 RBLR
? L?(1350Å)0.53
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Virial Mass Estimates MBHv2 RBLR/G

• Updated Scaling Relationships
• (calibrated to 2004 Reverberation MBH)
• CIV
• 1s uncertainty factor 3.5
• Hß

?
?
?
(H070 km/s/Mpc O? 0.7)
(see also Vestergaard 2002, and McLure Jarvis
2002 for MgII)
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NGC 5548
Highest ionization lines have smallest lags and
largest Doppler widths.

• ? Filled circles 1989 data from IUE and
  ground-based telescopes.
• ? Open circles 1993 data from HST and IUE.
• Dotted line corresponds to virial relationship
  with M 6 107 M?.

Peterson and Wandel 1999
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Virial Relationships

• All 4 testable AGNs comply
• NGC 7469 1.2 ?107 M?
• NGC 3783 3.0 ?107 M?
• NGC 5548 6.7 ?107 M?
• 3C 390.3 2.9 ?108 M?
• Scalings between lines
• vFWHM2(H?) lag (H?)
• vFWHM2(CIV) lag (CIV)
• R-L relation extends to high-z and high
  luminosity quasars
• spectra similar (e.g., Dietrich et al 2002)
• luminosities are not extreme
• R-L defined for 1042 1046
  (Vestergaard 2004)

Emission lines SiIV?1400, CIV?1549, HeII?1640,
CIII?1909, H??4861, HeII?4686
(Peterson Wandel 1999, 2000 Onken Peterson
2002)
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To first order quasar spectra look similar at all
redshifts
(Dietrich et al 2002)
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MBH-? Comparison of Active and Quiescent Galaxies

• Reverberation masses appear to fall along the MBH
  - ? relation for normal galaxies
• The scatter is also similar ? a factor of 3

Mass
Gals
AGNs
RM works!!
Bulge velocity dispersion
(Courtesy C. Onken)
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Masses of Distant Quasars

• Ceilings at MBH 1010 M? LBOL lt 1048
  ergs/s
• MBH 109 M? beyond space density drop at
  z 3

(H070 km/s/Mpc O? 0.7)
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Quasars

• Dramatic space density drop at z ?3
• Very luminous AGNs were much more common in the
  past.
• The quasar era occurred when the Universe was
  10-20 its current age.

(Peterson 1997)
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Masses of Distant Quasars

• Ceilings at MBH 1010 M? LBOL lt 1048
  ergs/s
• MBH 109 M? beyond space density drop at
  z 3

(H070 km/s/Mpc O? 0.7)
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Masses of Distant Quasars

• Ceilings at MBH 1010 M? LBOL lt 1048
  ergs/s
• MBH 109 M? beyond space density drop at
  z 3

(H070 km/s/Mpc O? 0.7)
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Masses of Distant Quasars

• Ceilings at MBH 1010 M? LBOL lt 1048
  ergs/s
• MBH 109 M? beyond space density drop at
  z 3

(H070 km/s/Mpc O? 0.7)
(DR3 Qcat Schneider et al. 2005)
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Luminosities of Distant Quasars
LEdd ? MBH
(H070 km/s/Mpc O? 0.7)
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Masses of Distant Quasars
Mass
LBOL
LBOL/LEdd
LBOL BC1 ?L?(1350Å) BC2 ?L?(4400 Å)
SDSS DR3
(H070 km/s/Mpc O? 0.7)
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Preliminary Mass Functions of Active Supermassive
Black Holes in Quasars

• Different samples show relatively consistent mass
  functions (shape, slope, normalization)
  (Vestergaard Osmer, in prep. Vestergaard, Fan,
  Osmer et al., in prep.)
• Goal constrain BH growth
  (with Fan, Osmer, Steeds, Weinberg)

• BQS 10 700 sq. deg B?16.16mag
• LBQS 454 sq. deg 16.0?BJ?18.85mag
• SDSS 182 sq. deg i ?20mag
• DR3 5000 sq. deg. i gt15, ?19.1, 20.2

(H070 km/s/Mpc O? 0.7)
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Preliminary Mass Functions of Active Supermassive
Black Holes in Quasars

• Different samples show relatively consistent mass
  functions (shape, slope, normalization)
  (Vestergaard Osmer, in prep. Vestergaard, Fan,
  Osmer et al., in prep.)
• Goal constrain BH growth
  (with Fan, Osmer, Steeds, Weinberg)

• BQS 10 700 sq. deg B?16.16mag
• LBQS 454 sq. deg 16.0?BJ?18.85mag
• SDSS 182 sq. deg i ?20mag
• DR3 5000 sq. deg. i gt15, ?19.1, 20.2

(H070 km/s/Mpc O? 0.7)
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Preliminary Mass Functions of Active Supermassive
Black Holes in Quasars

• Different samples show relatively consistent mass
  functions (shape, slope, normalization)
  (Vestergaard Osmer, in prep. Vestergaard, Fan,
  Osmer et al., in prep.)
• Goal constrain BH growth
  (with Fan, Osmer, Steeds, Weinberg)

• BQS 10 700 sq. deg B?16.16mag
• LBQS 454 sq. deg 16.0?BJ?18.85mag
• SDSS 182 sq. deg i ?20mag
• DR3 5000 sq. deg. i gt15, ?19.1, 20.2

(H070 km/s/Mpc O? 0.7)
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Preliminary Mass Functions of Active Supermassive
Black Holes in Quasars

• Locally mapped volume (R 100
  Mpc)
• MBH 3x109 M?
• SDSS color-selected sample and DR3 (Fan et
  al. 2001, Schneider et al. 2005)
• 9.5 quasars per Gpc3 with MBH 5x109
  M?
• ? need 25 times larger volume locally
  (R 290 Mpc)

(H070 km/s/Mpc O? 0.7)
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Improving the Scaling Relationships
Main goal improve scaling laws by reducing
scatter
R-L relation scatter dominates scatter in mass
scaling law

• Issues
• Host galaxy contamination
• Accuracy of MBH estimates
• R-L relation for CIV

(Data from Kaspi et al. 2005)
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Improving the Scaling Relationships
Main goal improve scaling laws by reducing
scatter
R-L relation scatter dominates scatter in mass
scaling law

• Issues
• Host galaxy contamination
• Accuracy of MBH estimates
• R-L relation for CIV

(Data from Kaspi et al. 2005)
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Main Results

• MBH in Active Nuclei can be determined to within
  an accuracy
• Low-z factor of 3 (measured)
• Higher z factor of 4 (estimated!!)
• MBH 109 M?, even at 4 ? z ? 6
• Ceilings LBOL lt1048 ergs/s, MBH ?1010 M?
• Mass Functions

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The M s Relationship

• Vittorini, Shankar, Cavalier 2005,
  astro-ph/0508640 (BH growth history from
  merger/feedback events simulation)
• Robertson et al. 2005, astro-ph/0506038 (mergers
  simulation)
• Di Matteo, Springel, Hernquist 2005, Nature,
  433, 604 (merger induced BH growth and
  starformation simulation)
• Springel, Di Matteo, Hernquist 2005, MNRAS,
  361, 776 (BH/star formation feedback
  simulations)
• Miralda-Escude Kollmeier 2005, ApJ 619, 30
  (stellar capture)
• Sazonov et al. 2005, MNRAS 358, 168 (radiative BH
  feedback)
• King 2003, ApJ 596, L27 (supercritical accretion,
  outflows)
• Adams et al. 2003, ApJ 591, 125 (rotating BH
  collapse model)
• .and many more..

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MBH-? Relation for Active and Quiescent Galaxies
Mass
Gals
AGNs
(Courtesy C. Onken)
Bulge velocity dispersion
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The M s Relationship
(Tremaine et al. 2002)
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Secondary Mass Estimation Methods
Via MBH - ?bulge Relation
Measured ?bulge CaII? ?8498, 8542, 8662Å
z lt 0.06
1 ? scatter 0.3 dex
M? ? ? 4.0
(Tremaine et al. 2002)
(Ferrarese et al 2001)
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Secondary Mass Estimation Methods
Via MBH - ?bulge Relation
1? scatter 0.7 dex
OIII?5007 FWHM ? ?bulge
(Nelson Whittle 1996 Nelson 2000)
Radio-louds

• Line asymmetries
• Outflows
• Radio sources
• (Interacting systems)

Tremaine slope
(Boroson 2003)
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Secondary Mass Estimation Methods
Via MBH - ?bulge Relation
Fundamental Plane ?e, re ? ?bulge ? MBH
1? scatter ? (? 0.7dex)

• Possibly significantly
• uncertain
• nuclear glare
• bulge/disk decomposition
• (e.g., McLeod Rieke 1995 Barth et al 2003)
• FP scatter (0.6dex for RGs
• e.g. Woo Urry 2002)
• - MBH - ?bulge scatter

Fundamental Plane ?
log re ?
FP(?,lt?egt) ?
(Barth et al 2003)
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Secondary Mass Estimation Methods
Via MBH - Lbulge Relation
MR ? Lbulge
1? scatter 0.45 - 0.6 dex

• Nuclear glare
• Bulge/disk decomposition
• (e.g., McLeod Rieke 1995 Barth et al 2003)
• Scaling relation scatter ?

MBH(dynamical)
MBH(scaling)
(McLure Dunlop 2001, 2002)
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Where Do We Go From Here?
Scaling Relations 0.5-0.6 R-L
relationships, understand
outliers
-- OIII FWHM 0.7 Understand
scatter outliers
-- Fundamental ?
Quantify establish higher Plane ?e, re

accuracy

• Via MBH Lbulge 0.6-0.7 Calibrate
  to reverberation mapped
• scaling rel.
  sources
• MR

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Using MgII as Proxy for BLR Velocity Dispersion

• Bridge 0.8 ? z ? 1.3 gap
• MgII and Hß have similar FWHMs
• Complications
• FeII contamination of line and continuum

Requires template fitting
(Vestergaard Wilkes 2001)
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To first order quasar spectra look similar at all
redshifts
(Dietrich et al 2002)
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Radius Luminosity Relations
To first order, AGN spectra look the same

• Same ionization
• parameter
• Same density

Kaspi et al (2000) data
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Radius-UV Luminosity Relationship for High-z
Quasars
M VFWHM2 RBLR/G ? ?
? 0.1?109 M? 4500km/s 33 lt-days
? ? RBLR-2 L
ltLgt 1047 ergs/s
Log ? ? Log n(H) ?
(Korista et al. 1997)
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Radius-UV Luminosity Relationship for High-z
Quasars
M VFWHM2 RBLR/G
? ? RBLR-2
(Dietrich et al. 2002)
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Reverberation Mapping

• Kinematics and geometry of the broad-line region
  (BLR) can be tightly constrained by measuring
  the emission-line response to continuum
  variations.
• Can be done with UV/optical lines.

NGC 5548, the most closely monitored Seyfert 1
galaxy
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Reverberation Mapping Results

• BLR sizes are measured from the cross-correlation
  time lags between continuum and emission-line
  variations.
• This gives the first moment of the transfer
  function.

Continuum
Emission line
NGC 5548, the most closely monitored Seyfert 1
galaxy
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Reverberation Mapping Results

• AGNs with lags for multiple lines show that
  highest ionization emission lines respond most
  rapidly ? ionization stratification
• Combine lag with line width to get a virial
  mass.

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Luminosities of Distant Quasars

• (Vestergaard 2004)

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Masses of Distant Quasars

• Ceiling at MBH ? 1010 M? LBOL lt 1048
  ergs/s
• MBH 109 M? beyond space density drop at z
  3

(Vestergaard 2004)
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AGNs in z 3 Lyman-break Galaxies
Broad-lined AGNs 1 of Lyman- break
galaxies (z 3) FWHM (CIV) 4700 km/s

• (Steidel et al. 2002)

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Masses of Distant Quasars II

• (Vestergaard 2004)

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Luminosities of Distant Quasars II

• (Vestergaard 2004)

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High Redshift Quasars I

• (based on Vestergaard 2004)

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High Redshift Quasars II

• (Vestergaard 2002b, ApJ, submitted)