1. Comparing with redshift surveys of galaxies

2. Redshift surveys –brief review CFA -----2000 galaxies (1983) Las Campanas ----25000 galaxies (1996) 2dF----250,000 galaxies (2003) SDSS----900,000 galaxies (2008?)

3. The role of different observations

7. Clustering and environment analysis The key is to account for the incompleteness correctly For example, two-point correlation function is measured very simply with DD(r)/RR(r)- 1, where DD and RR are the number of pairs of galaxies in the observed sample and in the random sample respectively; The key is to construct the random sample correctly

8. Incompleteness or selection effects Magnitude limited sample----radial selection effect; Limiting magnitude variation (0.1 typically) across the survey region; Survey boundary; Redshift measurement completeness; –Sampling rate; –Magnitude dependent redshift incompleteness –Fiber collision

12. Random sample A sample of the points randomly distributed spatially but with the same observational selection effects

13. 光度函数： – 单位体积、单位光度间隔内 的星系平均数目 –Schechter function: 两点相关函数： – 与均匀随机场相比，在距离 某个星系 r 处发现另一个星 系的额外几率 相对速度弥散： 背 景 介 绍背 景 介 绍 统计量

14. 红移空间畸变： 本征运动使星系看起来偏离膨胀背景 红移空间 2PCF ： 沿视向，大尺度压扁，小尺度拉伸 背 景 介 绍背 景 介 绍 测量方法

15. 背 景 介 绍背 景 介 绍

16. Redshift two-point correlation functions for DR2 (Li, C. et al. astroph/0509874; 0509873; see also Zehavi et al. 2005)

17. Dependence of CF on physical properties (Li et al. 2005a,b)

18. Luminosity dependence of the bias (r_p=2.7 Mpc/h; Zehavi et al. 2005) Stellar mass dependence (Li, et al 2005a,b) 星系成团的幅度，即 偏袒因子 b ，随光度 （上图）和恒星质量 （下图）的变化。

19. Velocity dispersion vs. physical properties (Li, C. et al. 2005b)

20. Velocity vs luminosity (Li, et al. 2005a,b)

21. Bimodal distribution in the color- magnitude diagram (SDSS)

22. Three ways of interpreting Halo Occupation Distribution (HOD) model (e.g. Jing et al. 1998; Yang et al 2003) Using galaxy formation models –Hydro/N-body simulations with star formation (physical processes; id of galaxies? e.g. V. Springel et al. 2005)Hydro/N-body simulations –Semi-analytical models of galaxy formation + N-body simulations (e.g. Kauffmann et al. 1999)

24. Physical processes of galaxy formation Formation of dark halos; gas shock heated; Gas cooled radiatively; Stars formed from cold gas; Massive stars short lived; form neutron stars and supernova explosions Explosions inject energy and metals into interstellar medium (hot+cold); heating and enrich---feedback effects Mergers of galaxies after their host halos merge; Black hole formation and its AGN feedback

27. Dark matter Galaxies: red for E; blue for spirals

28. 理 论 比 较理 论 比 较 构建 SDSS 的模拟样本 SDSS DR4  L500 L100+L300

29. Agreement after the reduction of faint satellites

30. Subhalo resolved: the bimodal color-mag distribution is much better reproduced

31. Summary Main features of galaxies can be explained in current galaxy formation models; High precision modeling for galaxy formation is still challenging, for very complicated physical process