1. Baryonic signature in the large-scale clustering of SDSS quasars Kazuhiro Yahata Dept. of Phys., University of Tokyo. Issha Kayo, Yasushi Suto, Matsubara Takahiko, Andy Connolly, Daniel Vanden Berk and others.

2. 1 Comparison of survey volumes GalaxyQuasar We can investigate ＞ 100Mpc/h structure.

3. EH ・ Eisenstein & Hu matter transfer function (1998) Theoretical matter 2PCF zero crossing baryon bump + -

4. B dependence Predicted Ω b -dependence Ω b ↑ ・ slope↓ ・ zero-crossing scale↑

5. Λ dependence Predicted Ω Λ -dependence Ω Λ ↑ ・ slope↓ ・ zero-crossing scale↑ We can derive constraints on Ω b and Ω Λ from these dependence.

6. Quasar sample selection ・ DR3 spectroscopic sample. ・ point source ・ Northern sky (80 ≦ α ≦ 300) ・ 15.0 ≦ m i, rc ≦ 19.1 ・ 0.16 ≦ z ≦ 2.24 Quasar sample selection

7. sample The quasar sample N QSO = 20303 2D distribution M i’rc N redshift

8. 2PCF 2PCF of SDSS quasars (Ω m =0.3,Ω Λ =0.7,h=0.7) It seems that the baryon bump exists in quasar 2PCF. ・ binning We derive constraints on Ω b from SDSS QSO clustering.

9. Fitting Proc Fitting procedure ・ h = 0.7, (0.6, 0.8) ・ spatially flat: Ω b + Ω Λ + Ω d =1 ・ scale independent bias: b QSO (z) →fitting parameters: Ω b ， Ω Λ ・ compute 2PCF (theory and observation) for grids of Ω b and Ω Λ. at linear regime, s ≧ 10Mpc/h ・ compute χ 2

10. z evolution Redshift evolution ・ Light-cone effect (Hamana, et al. 1998) ・ The Kaiser effect ・ evolution of scale independent bias All above effects are scale independent. Thus we can introduce effective quasar bias:

11. Chi2 h70 Result Δχ 2 Approximate fit: 2.6Ω b + Ω Λ = 0.9 Contours: 68%, 95%, 99.7%

12. Chi2 h60 Δχ 2 (h=0.60) 2.6Ω b + Ω Λ = 0.9 h-dependence is weak.

13. Chi2 h70 Δχ 2 (h=0.70) 2.6Ω b + Ω Λ = 0.9 h-dependence is weak.

14. Chi2 h8 ０ Δχ 2 (h=0.80) 2.6Ω b + Ω Λ = 0.9 h-dependence is weak.

15. Degeneracy Due to the huge errors of large scale bins, the zero- crossing scale is not well constrained yet. Future data are important in improving the constraints. The 2PCFs preferred from the current analysis.

16. Summary We derived constraints on Ω b and Ω Λ from SDSS QSO 2PCF. The result is approximately fitted to 2.6Ω b ＋ Ω Λ =0.9±0.1 Future quasar data will constrain the zero crossing scale well. We willbreak the degeneracy between Ω b and Ω Λ.

17. END End (Next: Dust Extinction)

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20. Systematic errors Possibilities of systematic error Redshift space distortion Finger of God The Kaiser effect (break of distant observer approximation) Error of redshift caused by mis-identification of emission lines. Fiber collision probably not important for large scale. Reddening correction The value of extinction is determined with assumption; 1) SED of elliptical galaxy (the effect is very small) 2) Old filter curve Sample selection I would like your comment or suggestion! Non-linearity New fitting formula is needed.

21. Future works ・ 2-dimensional 2PCF. ・ Include non-linearity ・ Halo occupation distribution To perform them, we need more dense sample →photometric quasar?

22. Chi2 h70 Δχ 2 (h=0.70)

23. Comp. SDSS Compute quasar 2PCF ●Landy-Szalay estimator ●Random Particle Distribution R.A. & DEC. ‥ random z ‥ observed z distribution N random ~ 600,000. Cumulative redshift distribution ●Jack-knife error

24. Region selection observed plate not observed used regionnot used RA and DEC. selection

25. Λ - OBS. Ω Λ dependence of observed 2PCF Ω Λ ↑ ・ slope ・ zero-crossing scale Separations between quasars also depend on cosmological parameters

26. h dependence h↑ ・ slope↑ zero-crossing scale is insensitive to h

27. z evolution eq Details of redshift evolution (1/3) ・ Light-cone effect (Hamana, et al. 1998) ・ The Kaiser effect observation theory

28. z evolution 2 Details of redshift evolution (2/3) ・ scale independent linear bias ・ Final expression?

29. z evolution 3 Details of redshift evolution (3/3) ・ Final expression? ・ …bias evolution model ex., Fry (1996) We need not to specify the bias evolution model for the fitting. It is future works. ↑scale independent ・ Final expression: ・ number of parameters is 3: Ω b ， Ω Λ ， b QSO,eff

30. 2pcf 2PCF We compute 2PCF of the SDSS quasars.

31. 2PCF 2PCF of SDSS quasars (Ω m =0.3,Ω Λ =0.7,h=0.7) Seems to indicate Ω b ≠0 ・ binning We derive constraints on Ω b from SDSS QSO clustering.