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The Highest-Redshift Quasars and Early Growth of Supermassive Black Holes

The Highest-Redshift Quasars and Early Growth of Supermassive Black Holes. Xiaohui Fan University of Arizona June 21, 2004. Existence of SBHs at the end of Dark Ages BH accretion History in the Universe?. Relation of BH growth and galaxy evolution?.

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The Highest-Redshift Quasars and Early Growth of Supermassive Black Holes

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

  2. Existence of SBHs at the end of Dark Ages BH accretion History in the Universe? Relation of BH growth and galaxy evolution? High-redshift Quasars, Black Holesand Galaxy Formation Resolved CO emission from z=6.42 quasar • 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

  6. 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,Omont,Brandt,Vestergaard,Eisenstein,Cool,Jiang,plus many SDSS collaborators

  7. 17,000 Quasars from the SDSS Data Release One 5 Ly a 3 2 CIV redshift CIII 1 MgII OIII Ha 0 wavelength 4000 A 9000 A

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

  9. 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~109-10 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 z>>10  co-formation and co-evolution of the earliest SBH and galaxies Fan et al. 2004

  10. 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

  11. 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

  12. 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)

  13. Gunn-Peterson Troughs in theHighest-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

  14. 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?

  15. 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

  16. Large Scale Distributionof Quasars SDSS 2dF

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

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

  19. 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

  20. 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

  21. BH Mass Estimates at high-redshift 1. Virial theorem:MBH = v2RBLR/G 2. Empirical Radius – Luminosity Relation allows estimates of RBLR:  MBH FWHM2 L0.7 accurate to a factor of 3 - 5 RBLR  Lλ(5100Å)0.7 • 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

  22. 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

  23. BH mass distribution 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

  24. BH Accretion Rate z>3 z<3

  25. 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. 2004 in prep

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

  27. 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 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

  28. 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

  29. 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. 2004 submitted Channel Maps  60 km/s 

  30. Summary • Quasar Luminosity Function • 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?

  31. 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

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