1. Russell Johnston Dept of Physics and Astronomy University of Glasgow

2. Edwin Hubble

3. Hubble measured the shift in colour, or wavelength, of the light from distant galaxies. Galaxy

4. Hubble measured the shift in colour, or wavelength, of the light from distant galaxies. Galaxy Laboratory

6. Hubble’s Law: 1929 Distant galaxies are receding from us with a speed proportional to their distance

7. Spacetime is expanding like the surface of a balloon. As the balloon expands, galaxies are carried farther apart

8. Although Hubble got the expansion law correct, his measurement of the current rate of expansion was quite wrong, and took many decades to correct.

9. Measuring the Hubble constant was a key project of the Hubble Space Telescope

10. More recently we have extended the Hubble diagram to great distances, using e.g. Supernovae…. Region probed by Hubble’s data

11. redshift ‘Speeding up’ model ‘Slowing down’ model Models with different shapes Hubble’s law for nearby supernovae measure of distance ….This has led to a remarkable discovery: The expansion of the Universe is speeding up!

12. What is driving the cosmic acceleration?…

14. Around Galaxies Distance from the Galaxy Centre (kpc) Orbital velocity (km/s) Typical size of galaxy disk

15. What we see What is really there.

16. We can also measure the redshifts of many galaxies. We call this a redshift survey. Redshift surveys can tell us many useful things: How galaxies cluster in space How galaxies evolve in time Different types of galaxy and where (and when) they are found How galaxies formed in the first place How much dark matter and dark energy… And

17. The First Redshift Surveys CfA Survey #1 : 1977 - 1982 CfA # 1 Surveyed a total of 1100 galaxies Marc Davis, John Tonry Dave Latham, John Huchra, Redshift range: out to z 0.0 5

18. Our own Galaxy de Lapparent, Geller, and Huchra (1986), ApJ, 302, L1

19. Filament Rich cluster Void?

21. CfA # 2 The First Redshift Surveys CfA Survey #2 : 1985 - 1995 John Huchra & Surveyed a total of 18,000 galaxies Margaret Geller Redshift range: out to z 0.05 208 Mpc

22. Redshift surveys (mid- 1980s) 1 Mpc = 3.26 milion light years

23. The largest structures in LCRS are much smaller than the survey size The size of the structures is similar in both samples LCRS 1995 (LAS CAMPANAS)

24. The First Redshift Surveys IRAS PSCz : 1992 – 1996, 15,000 galaxies Team originally consisted of around 24 members including: Catalogued over 83% of the sky - Will Sutherland, Steve Maddox, Largest full sky survey. Will Saunders, Carlos Frenk & Seb Oliver, Luis Teodoro.

25. Survey s…. The Next Generation Ran from 1998 to 2003. Used the multifibre spectrograph on the Anglo Australian Telescope. The survey covered two strips : NGP - SGP - Photometry was taken from the APM galaxy catalogue. Galaxies brighter than Recovered a total of 245,591 redshifts, 220,000 of which were galaxies out to The Two Degree Field Galaxy Redshift Survey (2dFGR S)

26. The Two Degree Field Galaxy Redshift Survey (2dFGR S) 35 collaborators fro UK, Australia and the US. including: Carlos Frenk, Matthew Colles, Richard Ellis, Ofer Lahav, John Peacock, Will Sutherland…. and these guys: Keith Taylor Simon Driver Karl Glazebrook Nick Cross Shaun Cole Peder Norberg Warrick Couch

28. The Two Degree Field Galaxy Redshift Survey (2dFGR S)

29. The Two Degree Field Galaxy Redshift Survey (2dFGR S)

32. = 100 Mpc diameter

33. The Sloan Digital Sky Survey (SDSS) Most ambitious ongoing survey to date. Began in early nineties and was due to complete in 2008 …. ish Uses a dedicated 2.5m telescope on Apache Point, new Mexico and a pair of spectrographs that measure more than 600 galaxy spectra in a single observation. Currently on data release 5 which contains 674749 galaxies. On completion will have surveyed over 1 million galaxies. The Survey has over 150 collaborators at 26 institutions

34. The Sloan Digital Sky Survey (SDSS)

35. SDSS CfA

36. Sloan Digital Sky Survey: The Footprint of the Survey

37. Area and Size of Redshift Surveys

38. CMBR fluctuations, 380000 years after the Big Bang, are the seeds of today’s galaxies The pattern of CMBR temperature fluctuations can be used to constrain the background cosmological model and its parameters Galaxies and Cosmology: the Basic Paradigm

39. CMBR fluctuations, 400000 years after the Big Bang, are the seeds of today’s galaxies The pattern of CMBR temperature fluctuations can be used to constrain the background cosmological model and its parameters Both the CMBR and present-day galaxy clustering favour : Galaxies and Cosmology: the Basic Paradigm Cold dark matter + non-zero cosmological constant

40. CMBR fluctuations, 400000 years after the Big Bang, are the seeds of today’s galaxies The pattern of CMBR temperature fluctuations can be used to constrain the background cosmological model and its parameters Both the CMBR and present-day galaxy clustering favour : Galaxies and Cosmology: the Basic Paradigm Cold dark matter + non-zero cosmological constant The Concordance Model

41. From Lineweaver (1998)

42. The cosmological constant now dominates over CDM and baryonic dark matter (i.e. atoms). It is not yet clear if is constant, or perhaps evolves with time. More generally, is referred to as ‘Dark Energy’.

43. Dark Energy Cold Dark Matter Atoms The cosmological constant now dominates over CDM and baryonic dark matter (i.e. atoms). It is not yet clear if is constant, or perhaps evolves with time. More generally, is referred to as ‘Dark Energy’.

44. Dark Energy Cold Dark Matter Atoms The cosmological constant now dominates over CDM and baryonic dark matter (i.e. atoms). It is not yet clear if is constant, or perhaps evolves with time. More generally, is referred to as ‘Dark Energy’. Unlike ‘normal’ matter, dark energy is gravitationally repulsive : it is causing the expansion of the Universe to accelerate.

45. Dark Energy Cold Dark Matter Atoms The cosmological constant now dominates over CDM and baryonic dark matter (i.e. atoms). It is not yet clear if is constant, or perhaps evolves with time. More generally, is referred to as ‘Dark Energy’. Unlike ‘normal’ matter, dark energy is gravitationally repulsive : it is causing the expansion of the Universe to accelerate. This affects the rate of growth of cosmic structure, which we can model via computer simulations

46. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect 140 Mpc 11 Gyr ago

47. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect 140 Mpc 8 Gyr ago

48. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect 140 Mpc Present day

49. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect 20 Mpc 11 Gyr ago

50. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect 8 Gyr ago 20 Mpc

51. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect Present day 20 Mpc

52. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect 11 Gyr ago 20 Mpc

53. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect 8 Gyr ago 20 Mpc

54. Hierarchical clustering: Galaxies form out of the mergers of fragments: CDM halos at high redshift. Clusters form where filaments and sheets of matter intersect Present day 20 Mpc

55. Which simulation model matches the observations?...

56. Hubble’s tuning fork classification We see spiral and elliptical galaxies…

59. Morphological Segregation Nowadays we find few spiral galaxies in rich clusters. This is thought to be because the spiral disks are disrupted by tidal forces…

61. Morphological Segregation Nowadays we find few spiral galaxies in rich clusters. This is thought to be because the spiral disks are disrupted by tidal forces… …Conversely, many ellipticals (and some spirals) may have formed from galaxy mergers. See talk by Bonnie Steves

62. A long time ago, in a galaxy far, far away…

68. z = 2.0 Light travel time = 10.3 billion years

69. z = 2.1 Light travel time = 10.5 billion years

70. z = 2.2 Light travel time = 10.6 billion years

71. z = 2.3 Light travel time = 10.8 billion years

72. z = 2.4 Light travel time = 10.9 billion years

73. z = 2.5 Light travel time = 11.0 billion years

74. z = 2.6 Light travel time = 11.1 billion years

75. z = 2.7 Light travel time = 11.2 billion years

76. z = 2.8 Light travel time = 11.3 billion years

77. z = 2.9 Light travel time = 11.4 billion years

78. z = 3.0 Light travel time = 11.5 billion years

79. z = 3.1 Light travel time = 11.6 billion years

80. z = 3.2 Light travel time = 11.6 billion years

81. z = 3.3 Light travel time = 11.7 billion years

82. z = 3.4 Light travel time = 11.8 billion years

83. z = 3.6 Light travel time = 11.9 billion years

84. z = 3.7 Light travel time = 11.9 billion years

85. z = 3.8 Light travel time = 12.0 billion years

86. z = 4.0 Light travel time = 12.1 billion years

87. z = 4.1 Light travel time = 12.1 billion years

88. z = 4.3 Light travel time = 12.2 billion years

89. z = 4.4 Light travel time = 12.2 billion years

90. z = 4.5 Light travel time = 12.3 billion years

91. z = 4.6 Light travel time = 12.3 billion years

92. z = 5.0 Light travel time = 12.5 billion years