Massive galaxies in massive datasets M. Bernardi, J. Hyde and E. Tundo

1. University of Pennsylvania Massive galaxies in massive datasets M. Bernardi, J. Hyde and E. Tundo

2. OUTLINE • Importance of Early-Type Galaxies • Stellar masses & Black Holes • The Hierarchical formation picture • Down-sizing and Dry mergers • Testing Dry mergers using scaling relations • Luminosities, Sizes, Velocity dispersions, Colors • Selection bias in the Mbh – L – s relations

3. Early-types don’t dominate number, but they do dominate stellar mass 57% 17% 43% 83% Renzini 2006

4. The most massive galaxies are red and dead

5. Super Massive Black Holes Connection with “AGN feedback”!! Ferrarese & Merritt 2000 Gebhardt et al. 2000

6. We need to find out when …. • stars were formed • the galaxy was assembled

7. Downsizing • Star formation only in smaller systems at late times • Environmental dependence important, but controversial (Thomas et al. 2005; but see Bernardi et al. 2006a; Bundy et al. 2006)

8. Old stellar population (OK for everybody!!) • ?? When were galaxies assembled ?? • Population of massive red galaxies seen even at z~1.5 (K20 Survey, VVDS) • Consistent with passive evolution (e.g. Cimatti et al. 2006, Bundy et al. 2006,Brown et al. 2006) OR • Still assembling at low z (e.g. Faber et al. 2006)? • In the hierarchical formation picture ….. the problem is to form stars, and assemble them into a single massive system, in a relatively short time (in this respect, LCDM is friendlier than SCDM) • How to do this?

9. OUTLINE • Importance of Early-Type Galaxies • Stellar masses & Black Holes • The Hierarchical formation picture • Down-sizing and Dry mergers • Testing Dry mergers using scaling relations • Luminosities, Sizes, Velocity dispersions, Colors • Selection bias in the Mbh – L – s relations

10. No AGN feedback New models match K-band luminosity function at z~0 AGN feedback Bower et al. 2006 (Durham) Croton et al. 2006 (Munich) Main change is to include AGN related effects

11. Latest generation of semi-analytic models, calibrated to z=0, able to match K-band luminosity function at z~1.5 Main change is to include AGN related effects  BCG Dry mergers common Massive Redheads? Passive evolution + Dry mergers Bower et al. 2006 (Durham)

12. Bimodality Satellite galaxies (not BCGs) • Models now produce reasonable color-magnitude relations • BCGs bluer? BCGs BCGs Bower et al. 2006 (Durham) Croton et al. 2006 (Munich)

13. OUTLINE • Importance of Early-Type Galaxies • Stellar masses & Black Holes • The Hierarchical formation picture • Down-sizing and Dry mergers • Testing Dry mergers using scaling relations • Luminosities, Sizes, Velocity dispersions, Colors • Selection bias in the Mbh – L – s relations

14. Brightest Cluster Galaxies Miller et al. 2005 • C4 cluster catalog • Uses both position and color info

16. Properties of early-type galaxies • Pairwise scaling relations • Faber-Jackson: L-s • Kormendy: Ie-Re • L-Re • Color - L • Inclusion of third parameter • The Fundamental Plane: Ie-Re-s Are they the same for BCGs????

17. BCGs show deviation from Kormendy relation Oegerle & Hoessel 1991 BCGs ETGs

18. Luminosity-Size relation • Upturn to larger sizes at large luminosities • Why? Oegerle & Hoessel 1991 R ~ L0.8 R ~ L0.6 ● BCGs ● High-s Dry merging? Bernardi et al. 2007a

19. L-R relation expected to depend on mass ratio and impact parameter of merging spheroids (Robertson et al. 2006)

20. Luminosity-s relation Flattening? Scatter correlates with size: consistent with Virial theorem: s2 ~ M/R ● 2 comp ●deV

21. The Fundamental Plane

22. Bimodality Satellite galaxies (not BCGs) • Models now produce reasonable color-magnitude relations • BCGs bluer? BCGs Bower et al. 2006 (Durham)

23. Color-Magnitude BCGs Bower et al. 2006 (Durham) Croton et al. 2006 (Munich)

24. SDSS measurements OUR measurements B03-Etypes C4-BCGs PL-BCGs

25. Color-Magnitude OUR-SDSS Models B03-Etypes C4-BCGs PL-BCGs Hyde & Bernardi 2007

26. Another class of massive galaxies? • BCGs are most luminous galaxies • What about galaxies with largest s: • these host the most massive BHs • constraints on formation mechanism (cooling cutoff) • Once again, to select a clean sample must worry about systematics!

27. Galaxies with the largest velocity dispersion ●Single/Massive Double ◊ BCG Sheth et al. 2003 Bernardi et al. 2006b Expect 1/300 objects to be a superposition

28. ‘Double’from spectrum and image

29. ‘Double’from spectrum, not image

30. ‘Single?’

31. HST images: with ACS-HRC SDSS J151741.7-004217.6 1’ 3” SDSS s = 412 ± 27 km/s HST

32. SDSS J204712.0-054336.7 1’ 3’ SDSS s = 404 ± 32 km/s HST

33. s = 383 ± 27 s = 385 ± 34 s = 369 ± 22 s = 385 ± 24 s = 395 ± 27 s = 402 ± 35 s = 404 ± 32 s = 407 ± 27 s = 408 ± 39 s = 413 ± 35 HST: ACS-HRC 28 single 15 multiple Large s not likely due to projection

34. Luminosity-Size relation Compared to BCGs, large s sample has smaller sizes Large s from extreme dissipation? Oegerle & Hoessel 1991 L ~ R0.8 L ~ R0.6 ● High-s ● BCGs Bernardi et al. 2006b

35. OUTLINE • Importance of Early-Type Galaxies • Stellar masses & Black Holes • The Hierarchical formation picture • Down-sizing and Dry mergers • Testing Dry mergers using scaling relations • Luminosities, Sizes, Velocity dispersions, Colors • Selection bias in the Mbh – L – s relations

36. Selection bias in the Mbh - L - s !

37. Discrepancy between Mbh function from L and s From L From s Tundo et al. 2007

38. What is the cause for this discrepancy? Selection bias in the s-L relation!! Bernardi et al. 2007b

39. Conclusions • Hierarchical models getting closer to observations … but not there yet • BCGs should be good testing ground • BCGs appear to be consistent with dry merger formation • Large s objects consistent with more dissipation • Selection bias in the Mbh – L - s