2. The Genesis and Star Formation Histories of Massive Galaxies Sept 27, 2004 P. J. McCarthy MGCT Carnegie Observatories

3. The PLAN The Nature of the Faint Red Galaxies Properties of K-selected Samples Evolution of Stellar Mass Density Formation Era for Massive Galaxies Star Formation Histories The Red Galaxies in Context

4. The Las Campanas IR Survey K < 20.8 BVRIz’JHK 1 sq. Degree Six Fields SA22 HDFS SA02 CDFS SA12 SA15 Chen, Markze, Firth, Ellis, Carlberg,Persson….

5. Color-Magnitude Diagram Stars 0.0 < z < 1.0 1.0 < z < 1.5 1.5 < z < 2.0 2700 sq. arcmin VROS EROS HEROS FROGS PMc 2 ARAA 2004

6. Number-Magnitude Relations Smith et al. R-K > 5.3 R-K > 6 I-K >3.5 4 4.5 5 5.5

7. Color-Color Diagrams K < 20.8 Moustakas et al. 1997

8. Color-Color Diagrams K < 20.8

13. Clustering of Red Galaxies

14. X-Rays 10% of EROs are CHANDRA Sources Locally 1% of Ellipticals are X-ray loud 2% of CHANDRA Sources are EROs Dramatic increase in AGN activity in red galaxies At redshifts greater than 1

15. <15% of EROs are detected with SCUBA at 850  m Typical flux is ~ 1mJy or 500M/yr SPITZER at 70  m detects ~ 50% Radio & Sub-MM ~30% are detected At cm wavelengths to ~ 15  Jy ~25M/yr Wehner et al. Mohan et al. Smail et al. 2003; Mohan et al. 2002 Yan et al. 04

16. CDFS SA12 SA15 The Gemini Deep Deep Survey I < 24.5 30 hour Exp. Four GMOS Fields Selection Criteria : 1. K 3.5 2.K 0.8 3.K > 20.6 Zph > 1.0 Targets ALL galaxies in 1 < z < 2 Epoch Abraham, Glazebrook, Crampton, Savaglio, Chen..

17. [OII] Redshifts from GDDS 23.7 < I(Vega) < 24.2

18. Interstellar Matter at z = 1.5 Red: Local Star burst composite (Tremonti et al.) Black: GDDS z = 1.5 I ~ 24.5 I-K < 3 composite Savaglio et al. 03

19. Stellar Absorption Features

20. Z =1.35 SDSS LRG

21. Evolution of Stellar Mass

22. 1  m Luminosity Function 1 < z < 1.5 2MASS Chen et al. 2003

23. Stellar Mass Determinations 100,000 Model Spectral Energy Distributions f(Age, SF history, abundance, reddening) Observed Spectral Energy Distributions, Redshifts Best-fit Template, range of templates Best-fit M/L, range Stellar Mass, range MKMK + 22 X =

24. The Most Massive Galaxies

25. The Evolution of Stellar Mass

26. SPECTRAL EVOLUTION AGES and FORMATION REDSHIFTS

27. Color Evolution Triangles show Red Cluster Sequence Field and Cluster Red Envelopes Similar

28. Color Evolution K Corrections Alone E, Sab, Scd, Irr

29. Color Evolution Exponential models  Gyr z f =10

30. Color Evolution Single burst models z f =10,5,3,2

31. Color Evolution Triangles show Red Cluster Sequence Field and Cluster Red Envelopes Similar

32. Color Evolution

33. 1.3 1.5 1.6 1.8 1.9 20 Old Galaxies at 1.3 < z < 2.2

34. The Oldest Galaxies =1.3

35. The Oldest Galaxies =1.3 =0.3

36. The Oldest Galaxies =1.3 53W091

37. The Oldest Galaxies =1.3 =1.8

38. The Oldest Galaxies =1.3 =1.8 2Gyr

39. Age Fitting for 20 Oldest Objects z > 1.3 Favor   [Fe/H] > 0 & A V > 0 Median age ~ 1.2 Gyr Median Z f = 2.4 but 30% have Z f >4 For Z/Z o = 3.5 For Z/Z o = 4 Intense Star Formation Phase at z > 2

40. Where are the progenitors? 50% of stellar mass density at z ~ 1.5 Peak star formation rates ~ 300 - 500M/yr Highly clustered = 2.4, but tail to z ~ 4 Progenitors have high SF density Higher than UV-selected populations More strongly clustered than LBGs Similar to n(z) for SCUBA sources

41. POST STARBURST GALAXIES and STAR FORMATION DENSITIES

42. Le Borgne et al.

44. Juneau et al.

45. Star Formation Histories Juneau et al. massive systems peak z >2 Intermediate mass systems peak z ~1.5 low masses peak z < 1

46. Near-Term Future SPITZER IRAC - start in Dec 04 GNIRS Neb. Abundances IMACS: 27’ dia. Field of View

47. Putting it all together Era of Massive Galaxy formation ~ 2 < z < 5 ~ 50% assembled since Most massive systems formed first Downsizing important

50. Age Fitting 1.Closed Box Models: Primordial abundances, recycling  Gyr 2. Single Stellar Population Models: Z/Z 0 = 0.2 -2 Fixed  Gyr Ages > 6 Gyr! 0.9 - 3.5Gyr

51. Evolution and Color Dependence Red color selection or E morphological selection Blue color selection or late type morphological selection LCRS CNOC2 CFRS CFGRS LBG

52. Evolution and Color Dependence Kauffmann et al 99 Early types Star forming galaxies LCRS CNOC2 CFRS CFGRS LBG

53. How are Galaxies Formed? Monolithic Collapse ala ELS Hierarchical Assembly

54. When did they Form? Gemini Press Office

55. Conclusions Population: 50-80% old galaxies Counts & LF: little evolution to z ~ 1.5 X-rays: Black hole growth in massive galaxies Masses: Modest growth at high mass end Colors: Red envelope: passive evolution Ages: Early but plausible formation redshifts Progenitors: Sub-mm/Far-IR Galaxies? Early Formation for Massive Galaxies

56. Photometric Redshifts from LCIR H.-W. Chen et al in prep  z)/(1+z) = 0.08

57. The Most Massive Galaxies

58. The Evolution of Stellar Mass Log Mass Density M/Mpc3

60. Color Evolution

61. Absorption Line Spectra I = 24.0 Z = 1.67 I = 23.7 Z = 1.56 I = 24.2 Z = 1.39 Rest Wavelength

62. The Oldest Galaxies =1.3 =1.8 =0.3

63. The Most Massive Galaxies Glazebrook et al. 2004, Nature

64. Color Evolution

65. The Oldest Galaxies =1.3 =1.8