Probing Cosmic Evolution with Distant Quasars

1. Probing Cosmic Evolution withthe Most Distant Quasars Xiaohui Fan University of Arizona Apr 18, 2010 Collaborators: Jiang, Carilli, Kurk, Rix, Strauss, Vestergaard, Walter, Wang Background: 46,420 Quasars from the SDSS Data Release Three

2. 46,420 Quasars from the SDSS Data Release Three 5 Ly forest 3 Ly 2 CIV redshift CIII MgII FeII 1 FeII OIII H 0 wavelength 4000 A 9000 A

3. Almost 50 Years Ago:First Quasar: 3C 273 by Maarten Schmidt

4. Quest to the Highest Redshift

5. Quest to the Highest Redshift 090423 080913 050904 000131 GRBs 970228

6. 30 at z>6 60 at z>5.5 >100 at z>5

7. z~6: Crucial Transition in quasar evolution • Evolution of quasar density and accretion rate: • Formation of the first billion solar mass BHs? • Dust-free quasars • Connection to the earliest galaxies? • Gas and star formation in host galaxies • Evolution of M-σ relation? • Evolution of IGM neutral fraction • End of reionization epoch?

8. Theorists Tell us • These luminous z~6 quasars: • The most massive system in early Universe • Living in the densest environment • BH accreting at Eddington • Host galaxies have ULIRG properties with maximum starburst Li et al. 2007

9. Strong density evolution Density declines by a factor of ~40 from between z~2.5 and z~6 Black hole mass measurements MBH~109-10 Msun Mhalo ~ 1012-13 Msun rare, 5-6 sigma peaks at z~6 (density of 1 per Gpc3) Quasars accreting at maximum rate Quasar luminosity consistent with Eddington limit Quasar Evolution at z~6 Low-z z~6 Fan et al. 2006, 2010

10. Puzzle 1: Are there luminous quasars at z>>7 • Black Holes do not grow arbitrarily fast • Accretion onto BHs dicitated by Eddington Limit • E-folding time of maximum supermassive BH growth: 40 Myr • At z=7: age of the universe: 800 Myr = maximum 20 e-folding • Billion solar mass BH at z>7 • Non-stop, maximum accretion from 100 solar mass BHs at z=15 (collapse of first stars in the Universe) • Theoretically difficult for formation of z>7 billion solar mass BHs • What if we find them: • Direct collapse of “intermediate” mass BHs? • More efficient accretion model “super-Eddington”?

11. Puzzle 2: non-evolution of quasar (black hole) emission z~6 composite Ly a Low-z composite NV Ly a forest OI SiIV XF et al. 2010 Jiang, XF et al. 2008 • Rapid chemical enrichment in quasar vicinity • Quasar env has supersolar metallicity : no metallicity evolution • High-z quasars are old, not yet first quasars, and live in metally enriched env similar to centers of massive galaxies

12. When did the first quasar form? Dust: emitting in infrared radiation from X-ray to radio as a result of black hole accretion and growth

13. Disappearance of Dust Torus at z~6? typical J0005 3.5m 4.8m 5.6m 8.0m 16m 24m • quasars with no hot dust • Spitzer SEDs consistent with disk continuum only • No similar objects known at low-z • no enough time to form hot dust tori? Or formed in metal-free environment? Jiang, XF et al. 2010

14. Epoch of first quasars? • Dust-free quasars: • Only at the highest redshift • With the smallest BH mass • First generation supermassive BHs from metal-free environment? • How are they related to PopIII? Dust/Bolometric Dust/Bolometric Jiang, XF et al. 2010 BH mass

15. High-redshift quasars live in the center of star-forming galaxies CO • J1148 (z=6.42) - Spatially resolved CO and [CII] emissions: • Size: ~1.5 kpc • Star formation rate of: ~1000 Msunyr-1kpc-2 • theoretically close to maximum star formation rate ? • Gas supply exhaused over a few tdyn • Similar SF intensity to the brightest local starburst (Arp 200) but 100 times larger! 1kpc • J1148 (z=6.42): • CO line width ~300 km/s • Dynamical mass ~1011Msun? • BH formed earlier than completion of galaxy assembly? Walter et al. 2004 Walter et al. 2009

16. reionization Two Key Constraints: WMAP 5-yr: zreion=11+/-3 2. IGM transmission: zreion > 6 From Avi Loeb

17. First detection of Gunn-Peterson Effect

18. Evolution of Lyman Absorptions at z=5-6 transparent opaque z = 0.15

19. Optical depth evolution accelerated z<5.7:  ~ (1+z)4.5 z>5.7:  ~ (1+z)>11 > Order of magnitude increase in neutral fraction of the IGM  End of Reionization Dispersion of optical depth also increased Some line of sight have dark troughs as early as z~5.7 But detectable flux in ~50% case at z>6 End of reionization is not uniform, but with large scatter Accelerated Evolution at z>5.7 (1+z)11 (1+z)4.5 XF et al. 2006

20. Beyond Gunn-Peterson Optical Depth:HII Region Sizes zem • Gunn-Peterson test saturates at z>6 • Size of HII region Rs ~ (LQ tQ / fHI )1/3 • HII region size decreases by ~ 3 from z=5.7 to 6.4 • Best estimate: fHI ~ a few percent at z~6 • Can be applied to higher z and fHI with lower S/N data • Model uncertainties due to radiative transfer Carilli et al. 2010 HII region size z

21. Probing Reionization History WMAP

22. Roads ahead • Luminous quasars probe the evolution of the most massive systems in the early universe • Important changes were happening at z~6-7 • Timescale constraints on billion solar mass BH growth • Evidence of youngest quasar structure • End of reionization epoch with order of magnitude (or more?) increase in IGM neutral fraction • Discovery (or lack of ) z~7 quasars might reveal new surprises • Requires new generation of large IR sky surveys • Quasars and GRBs are complimentary probes to the peak of reionization epoch • GRB probes pristine, low mass galaxies and can reach high-z faster