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Quasar Surveys -- From Sloan to SNAP

Quasar Surveys -- From Sloan to SNAP. Xiaohui Fan University of Arizona May 17, 2004. Quasars and Galaxy Formation. The Study of Quasars Probes: Accretion history of BHs in the Universe Relation of BH growth and galaxy evolution State of intergalactic medium

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Quasar Surveys -- From Sloan to SNAP

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  1. Quasar Surveys-- From Sloan to SNAP Xiaohui Fan University of Arizona May 17, 2004

  2. Quasars and Galaxy Formation • The Study of Quasars Probes: • Accretion history of BHs in the Universe • Relation of BH growth and galaxy evolution • State of intergalactic medium • History of reionization probing the end of cosmic dark ages

  3. Quasar Surveys in the last decade • 1996: Veron-Veron catalog • 8609 quasars • 2833 AGNs • 2dF quasar survey (1997 – 2002) • 25,000 quasars at z<2.8 • SDSS quasar survey (1999 – 2005+) • Currently: >50,000 quasars • Goal: 100,000 quasars • z<6.5 • Next? • Fainter magnitude • Higher redshift

  4. 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

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

  6. Evolution of LF shape • At low-z: 2dF results show that LF is well fit by double power law with pure luminosity evolution • At z~4: quasar luminosity function much FLATTER than LF at z~2

  7. Clustering of Quasars • What does quasar clustering tell us? • Bias factor of quasars  average DM halo mass • A biased large scale power spectrum at high-z • 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

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

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

  10. The HighestRedshift Quasars Today • z>4: ~700 known • z>5: ~30 • z>6: 7 • SDSS i-dropout Survey: • By Spring 2004: 6000 deg2 at zAB<20 • Fourteen luminous quasars at z>5.7 • 20 – 40 at z~6 expected in the whole survey Total Discoveries SDSS Discoveries

  11. Quasar Density at z~6 • Based on nine z>5.7 quasars: • Density declines by a factor of ~20 from z~3 • 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 • Using Eddington argument, 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

  12. Quasars are boring… The Lack of Evolution in Quasar Intrinsic Spectral Properties Ly a NV OI Ly a forest SiIV High-z quasars and their environments matures early on

  13. 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

  14. Black Hole Mass Function Mass function for different redshifts Vestergaard et al. 2004 in prep

  15. 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

  16. reionization From Avi Loeb

  17. Gunn-Peterson troughs confirmed by new z>6 quasars

  18. Strong Evolution ofGunn-Peterson Optical Depth Transition at z~6? Fan et al. 2003

  19. Constraining the Reionization Epoch • Neutral hydrogen fraction • Volume-averaged HI fraction increased by >100 from z~3 to z~6 • Mass-averaged HI fraction > 1% • At z~6: • Last remaining neutral regions are being ionized • The universe is >1% neutral • Marks the end of reionization epoch?? mass ave. vol. ave Fan et al. in prep

  20. The end of dark ages • CMB polarization shows: substantial ionization by z~17: • Combining GP with CMB  reionization history: • Reionization last from 20 to 6? (600 million years) ? • Reionization is not a phase transition • Reionization seems to be more complicated by the simplest theory

  21. Quasar Survey in Space? • Limitations of current generation quasar surveys: • Shallow: Only probing the most luminous quasars  majority of high-z quasars have not been detected! • Evolution of faint quasars unknown • Majority of UV background at high-z not detected yet • Optical: Highest redshift limit is ~6.5

  22. Quasar Survey in Space? • Deep: • Sampling the entire quasar population • Probing “normal” BHs in average galaxies • Possible with LSST • Infrared: Breaking the z=7 Barrier • Emergence of the first luminous quasars in the Universe • Probing the history of the cosmic reionization • Key issue: • How effectively can quasar be selected photometrically, without a large spectroscopic survey?

  23. Quasar Photo-z? • Lyman break technical efficient at z>3 • At low-z, strong emission line passing through pass-bands causes bumps in the color-z relation • Esp. 3000A bump

  24. Quasar Photo-z usingSDSS photometry • Weinstein et al. 2004, Richards et al. 2004 show: • With good (sigma <0.05) photometry • 86% photo-z correct to within 0.3 • 65% photo-z correct to within 0.1 • 95% of photometrically-selected quasars are real quasars confirmed by spectroscopy

  25. X-ray vs. Optical LF • There is very little overlap… • do faint quasars evolve • differently from luminous quasars?

  26. Evolution of Quasar/AGN Density Optical, high-luminosity X-ray, low-luminosity

  27. Luminosity Function:AGNs and QSOs z=0 Hao et al. 2004

  28. Probing the end of dark ages • Panoramic: • 7000 sq.deg, effective selection down to 24.5 • z~3 quasars: 200 – 400 per sq. deg • Hundreds of z~6 quasars • Maybe 10 luminous quasars at z = 9 – 10?

  29. Probing Reionization History SNAP Spectrograph • Double reionization model: • Early reionization at z>10 • Second dark age at z<8.5

  30. Quasar Astrophysics • Large scale structure  host galaxy masses • Quasar clustering • Quasar weak lensing • Strong lensing • Variability  revebretion mapping and BH mass • High resolution imaging of host galaxies

  31. GEMS/COMBO-17: quasar host galaxies Kormendy relation from GEMS host galaxies Wisotzki et al. 2004

  32. Summary • Current quasar survey shows • Strong evolution of luminous quasar number density • Strong clustering of luminous quasars • Existence of billion solar mass BHs at z~6 • Emergence of Gunn-Peterson effect indicates the end of reionization epoch by z~6 • A wide-field space-based quasar survey will • Probe the evolution of faint quasars and the evolution of UV background at high-z • Reveal the evolution of first luminous quasars in the Universe • Map the history of reionization at z = 6 – 10 • Relation between quasar activity and galaxy formation

  33. SNAPS Courtesy of Arizona graduate students

  34. SDSS: Structure Function

  35. Structure function turnover

  36. Strong Evolution ofGunn-Peterson Optical Depth Transition at z~6? Fan et al. 2003

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