The HighestRedshift Quasars and Early Growth of Supermassive Black Holes

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The Highest-Redshift Quasarsand Early Growth of
Supermassive Black Holes

• Xiaohui Fan
• University of Arizona
• June 21, 2004

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High-redshift Quasars, Black Holesand Galaxy
Formation
Resolved CO emission from z6.42 quasar

• Existence of SBHs at the end of Dark Ages
• BH accretion History in the Universe?

• Relation of BH growth and galaxy evolution?

• Quasars role in reionization?

Evolution of Quasar Density
Detection of Gunn-Peterson Trough
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Exploring the Edge of the Universe
New z7 galaxies

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Courtesy of Arizona graduate students
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The Highest Redshift Quasars Today

• z4 900 known
• z5 50
• z6 8
• SDSS i-dropout Survey
• By Spring 2004 6000 deg2 at zAB
• Sixteen luminous quasars at z5.7
• Five in the last year
• 30 50 at z6 expected in the whole survey

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Outline

• The first luminous quasars
• Evolution of faint quasars
• Role in reionization
• Quasar clustering at high-redshift
• Constraining host properties
• Lack of quasar spectral evolution
• Metallicity and Chemical Evolution
• Early Black Hole Growth
• Is there an upper limit on the BH mass?
• Probing the growth of host galaxies
• Dust, gas and star-formation
• Collaborators Strauss,Schneider,Richards,Gunn,
  Becker,White,Rix,Pentericci,Walter,Carilli,Cox,Omo
  nt,Brandt,Vestergaard,Eisenstein,Cool,Jiang,plus
  many SDSS collaborators

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17,000 Quasars from the SDSS Data Release One
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Ly a
3
2
CIV
redshift
CIII
1
MgII
OIII
Ha
0
wavelength
4000 A
9000 A
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Evolution of Quasar Luminosity Function
SFR of Normal Gal
Exponential decline of quasar density at
high redshift, different from normal galaxies


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Quasar Density at z6

• Based on 6000 sq. deg of SDSS i-dropout survey
• Density declines by a factor of 40 from between
  z2.5 and z6
• It traces the emergence of the earliest
  supermassive BHs in the Universe
• Cosmological implication
• MBH109-10 Msun
• Mhalo 1013 Msun
• How to form such massive galaxies and assemble
  such massive BHs in less than 1Gyr??
• The rarest and most biased systems at early times
• The initial assembly of the system must start at
  z10
• ? co-formation and co-evolution of the earliest
  SBH and galaxies

Fan et al. 2004
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Evolution of LF shape

• At low-z
• 2dF LF is well fit by double power law with
  pure luminosity evolution ? downsizing of BH
  activities
• What about high-redshift?
• Does the shape of quasar LF evolve?
• Do X-ray and optically-selected samples trace the
  same population?
• Key how does faint quasars at high-z evolve?

X-ray, low-luminosity
Optical, high-luminosity
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SDSS2

• SDSS Southern Deep Spectroscopic Survey
• 270 deg along Fall Equator in the Southern
  Galactic Cap
• Down to 25 mag in SDSS bands with repeated
  imaging
• Spectroscopic follow-up using 300-fiber Hectospec
  spectrograph on 6.5-meter MMT
• Quasar and early-type galaxy survey with
  flux-limit about 3 mag deeper than SDSS main
  survey
• Few hundred faint quasars at z3 LF and
  clustering
• 10 20 at z6

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High-z QLF from Precursor Survey
z 4.5

• High-z quasar LF different from low-z
• Different triggering mechanism at low and high-z?
• Constraint quasar accretion efficiency?
• Combining with COMBO-17 and GOODS
• Break in LF at M 24?
• Constrain quasar contribution to the reionization

(high-z)
(low-z)
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Gunn-Peterson Troughs in theHighest-redshift
Quasars

• Strong, complete Lya and Lyß absorption in the
  five highest redshift quasars at z6.1
• Neutral fraction of IGM increases dramatially at
  z6
• The end of reionization epoch

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What Reionized the Universe?

• Based on SDSS quasar luminosity function
• UV photons from luminous quasars and AGNs are not
  the major sources that ionized the universe
• Consistent with limit from X-ray stacking of
  Lyman break galaxies in the UDF
• Star-formation? Soft X-ray from mini-quasars?

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Clustering of Quasars

• What does quasar clustering tell us?
• Correlation function of quasars vs. of dark
  matter
• Bias factor of quasars ? average DM halo mass
• Clustering probably provides the most effective
  probe to the statistical properties of quasar
  host galaxies at high-redshift
• Combining with quasar density ? quasar lifetime
  and duty cycle

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Large Scale Distributionof Quasars
SDSS
2dF
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Quasar Two-point Correlation Function from SDSS
at zVan den Berk et al. in preparation
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Evolution of Quasar Clustering
Fan et al. in preparation
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The Lack of Evolution in Quasar Intrinsic
Spectral Properties

Ly a
NV
OI
SiIV
Ly a forest

• Rapid chemical enrichment in quasar vicinity
• High-z quasars and their environments matures
  early on

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Chemical Enrichment at z6?

• Strong metal emission ? consistent with
  supersolar metallicity
• NV emission ? multiple generation of star
  formation
• Fe II emission ? might be from metal-free Pop III
  
• Question what exactly can we learn from
  abundance analysis of these most extreme
  environment in the early universe?

Fan et al. 2001
Barth et al. 2003
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BH Mass Estimates at high-redshift

• 1. Virial theorem MBH v 2 RBLR/G
• 2. Empirical Radius Luminosity Relation
  allows estimates of RBLR
• 
  
• ? MBH ? FWHM2 L? 0.7 accurate to a factor
  of 3 - 5

RBLR ? L?(5100Å)0.7

• z
• z 0.7 3 MgII
• z3 CIV

Lack of spectral evolution in high-redshift
quasars ? virial theorem estimate valid at
high-z
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Early Growth of Supermassive Black Holes
Formation timescale (assuming Eddington)
Vestergaard 2004
Dietrich and Hamann 2004

• Billion solar mass BH indicates very early
• growth of BHs in the Universe

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BH mass distribution
CIV
? Upper Limit????
LM
Fan et al. 1000 quasars at z3
McLure et al. SDSS DR 1
There might be an upper envelop of BH Mass at
MBH few x 1010 M_solar
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BH Accretion Rate
z3
z 27
Black Hole Mass Function?

• Is there a real upper limit of BH mass?
• Whats the distribution of BH accretion
  efficiency at high-redshift?
• How does accretion history trace host galaxy
  assembly?

Vestergaard et al. 2004 in prep
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Probing the Host Galaxy Assembly
? Dust torus
Spitzer
ALMA

• Cool Dust in
• host galaxy

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Sub-mm and Radio Observationof High-z Quasars

• Probing dust and star formation in the most
  massive high-z galaxy
• Using IRAM and SCUBA 40 of radio-quiet quasars
  at z4 detected at 1mm (observed frame) at 1mJy
  level
• Combination of cm and submm
• ? submm radiation in
• radio-quiet quasars
• come from thermal
• dust with mass 108 Msun
• If dust heating came from starburst
• ? star forming rate of
• 500 2000 Msun/year
• ?Quasars are likely sites
• of intensive star formation

Arp 220
Bertoldi et al. 2003
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• Submm and CO detection
• in the highest-redshift quasar
• Dust mass 108 109Msun
• H2 mass 1010Msun
• Star formation rate 103/yr
• co-formation of SBH and
• young galaxies

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High-resolution CO Observation of z6.42 Quasar
VLA CO 32 map

• Spatial Distribution
• Radius 2 kpc
• Two peaks separated by 1.7 kpc
• Velocity Distribution
• CO line width of 280 km/s
• Dynamical mass within central 2 kpc 1010 M_sun
• Total bulge mass 1011 M_sun
• BH formed before
• galaxy assembly?

1 kpc
Walter et al. 2004 submitted
Channel Maps
? 60 km/s ?
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Summary

• Quasar Luminosity Function
• Strong evolution from z3 to 6
• Relatively flat LF at high-redshift
• UV photons from quasars not important to
  reionization
• Quasar clustering
• Clustering strength of flux-limited sample
  increases with redeshift
• High-redshift quasars are strongly biased ? halo
  mas
• Lack of quasar spectral evolution
• Quasar environment matured very early, with rapid
  chemical enrichment
• Black hole mass estimates from virial theorem
  probably reliable
• Early Black Hole Growth
• 1010 M_sun BH existed at z6
• Is there a real upper limit?
• Radio and sub-mm probes of host galaxies
• High-redshift quasars are sites of specticular
  star-formation 1000 M_sun/yr
• First resolved z6 host galaxy BH growth before
  galaxy assembly?

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Whats Next?

• Environment and host galaxies of z5 quasars
• Spitzer ALMA gas physics, star formation and
  kinematics
• The First Quasar?
• Assuming SDSS QLF and Eddington accretion, the
  first 1010 M_sun BH in the observable Universe at
  z8.5 to 11.5
• Within reach of the next generation ground and
  space-based IR surveys