1. Xiaohui Fan University of Arizona June 21, 2004
The Highest-Redshift Quasars and Early Growth of Supermassive Black Holes
Xiaohui Fan
University of Arizona
June 21, 2004

2. High-redshift Quasars, Black Holes and Galaxy Formation
Resolved CO emission from z=6.42 quasar
Existence of SBHs at the end of Dark Ages
BH accretion History in the Universe?
Relation of BH growth and galaxy evolution?
Quasar’s role in reionization?
Evolution of Quasar Density
Detection of Gunn-Peterson Trough

3. Exploring the Edge of the Universe
New z~7 galaxies

4. Courtesy of Arizona graduate students

5. The Highest Redshift Quasars Today
z>4: >900 known
z>5: >50
z>6: 8
SDSS i-dropout Survey:
By Spring 2004: 6000 deg2 at zAB<20
Sixteen luminous quasars at z>5.7
Five in the last year
30 – 50 at z~6 expected in the whole survey

7. Outline The first luminous quasars Quasar clustering at high-redshift
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,Omont,Brandt,Vestergaard,Eisenstein,Cool,Jiang,plus many SDSS collaborators

8. 17,000 Quasars from the SDSS Data Release One5
Ly a 3 2
CIV
redshift
CIII 1
MgII
OIII Ha
wavelength
4000 A
9000 A

9. Evolution of Quasar Luminosity Function
SFR of Normal Gal
Exponential decline of quasar
density at high redshift, different
from normal galaxies

10. Quasar Density at z~6 Based on 6000 sq. deg of SDSS i-dropout survey:
Density declines by a factor of ~40 from between z~2.5 and z~6
It traces the emergence of the earliest supermassive BHs in the Universe
Cosmological implication
MBH~ 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 z>>10
 co-formation and co-evolution of the earliest SBH and galaxies
Fan et al. 2004

11. Optical, high-luminosity
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

12. 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 z>3: LF and clustering
10 – 20 at z~6

13. High-z QLF from Precursor Survey
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)

14. Gunn-Peterson Troughs in the Highest-redshift Quasars
Strong, complete Lyα and Lyβ absorption in the five highest redshift quasars at z>6.1
Neutral fraction of IGM increases dramatially at z>6
The end of reionization epoch

15. 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?

16. 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

17. Large Scale Distribution of Quasars
SDSS
2dF

18. Quasar Two-point Correlation Function from SDSS at z<2.5
Van den Berk et al. in preparation

19. Evolution of Quasar Clustering
Fan et al. in preparation

21. The Lack of Evolution in Quasar Intrinsic Spectral Properties
Ly a NV
Ly a forest OI
SiIV
Rapid chemical enrichment in quasar vicinity
High-z quasars and their environments matures early on

22. Chemical Enrichment at z>>6?
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

23. 1. Virial theorem: MBH = v 2 RBLR/G
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 accurate to a factor of 3 - 5
RBLR  Lλ(5100Å)0.7
A bi-product of reverberation mapping is the Radius – Luminosity relationship. Kaspi et al found empirically that the radius scales to the optical continuum luminosity to the power of 0.7. That means that in principle the BH mass can be estimated if we have measurements of the line width and the continuum luminosity.
The question is: how well can we estimate the mass with a single-epoch spectrum?
z<0.7 : Hβ
z= 0.7 – 3: MgII
z>3: CIV
Lack of spectral evolution in high-redshift quasars 
virial theorem estimate valid at high-z

24. 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

25. BH mass distribution There might be an upper envelop
CIV
 Upper Limit????
L~M
Fan et al. >1000 quasars at z>3
McLure et al. SDSS DR 1
There might be an upper envelop
of BH Mass at MBH ~ few x 1010 M_solar

26. BH Accretion Rate
z>3
z<3

27. Black Hole Mass Function?
Is there a real upper limit of BH mass?
What’s the distribution of BH accretion efficiency at high-redshift?
How does accretion history trace host galaxy assembly?
Vestergaard et al in prep

28. Probing the Host Galaxy Assembly
 Dust torus
Spitzer
ALMA
Cool Dust in
host galaxy

29. Sub-mm and Radio Observation of 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 z>4 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

30. in the highest-redshift quasar: Dust mass: 108 – 109Msun
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

31. High-resolution CO Observation of z=6.42 Quasar
VLA CO 3—2 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
< M-sigma prediction
BH formed before
galaxy assembly?
1 kpc
Walter et al submitted
Channel Maps
 60 km/s 

32. Summary Quasar Luminosity Function Quasar clustering
Strong evolution from z~3 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 z>6
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 z~6 host galaxy: BH growth before galaxy assembly?

33. What’s Next? Environment and host galaxies of z>5 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 z=8.5 to 11.5
Within reach of the next generation ground and space-based IR surveys