The Expanding Universe Steven Beckwith Space Telescope Science Institute US Ambassador’s Residence, New Zealand July 8, 2002

2 The Milky Way

Galileo and the Milky Way in 1609

Edwin Hubble & Galaxies

5 Doppler Shifts and Galaxy Velocities z = change in wavelength wavelength speed  z x speed of light Measure the redshift, z. Infer the speed, v Doppler shift of light speed

6 D = 4D 0 v = 4v 0 D = 2D 0 v = 2v 0 D = 2.5D 0 v = 2.5v 0 D = 2.3D 0 v = 2.3v 0 D = 0.9D 0 v = 0.9v 0 v = 1.4v 0 D = 1.4D 0 D = 3.1D 0 v = 3.1v 0 Hubble 1929 Velocity = H 0 x Distance

7 Modern Hubble diagram Riess, Press, & Kirshner (1996) Velocity = H 0 x Distance H 0 = 70 km/s/Mpc = 23 km/s/10 6 -light-yr

The Hubble Deep Field STScI Science Project: R. Williams. et al. (1997) 6.3 z= z= z= z= z= z= z=5.60 Age of obs. (Gyr) T now = 15 Gyr

9 HDF galaxies look similar in rest- frame UV and rest- frame optical. Early structures were fragments, the pieces of galaxies to be assembled. HDF galaxy shapes Left:Visual Right:Infrared

10 Mice galaxies

11 The Tadpole Galaxy

12 The Tadpole Galaxy

13 GOODs Legacy & Treasury Programs v Observations 300 arcmin 2 in two fields: HDF-N, CDF-S300 arcmin 2 in two fields: HDF-N, CDF-S SIRTF: microns (IRAC+MIPS), 600 hoursSIRTF: microns (IRAC+MIPS), 600 hours HST: 4 fileters, 500 orbits ACS, near HDF depthHST: 4 fileters, 500 orbits ACS, near HDF depth Chandra: 2 million seconds; XMM: ~ 0.5 million secondChandra: 2 million seconds; XMM: ~ 0.5 million second NorthSouth  Science  Evolution of galaxies, 1 Gyr to 7 Gyr (6 > z > 1)  SN Ia detection via scheduling: PiggyBack survey (Riess et al.)  AGN morphologies  Upgrades: wider fields for AGN, weak-lensing, DEEP fields Mark Dickinson, Mauro Giavalisco & co.

14 GEMS Galaxy Evolution from Morphologies and SEDs 600 ACS pixels = 30 ” 30 ’ field Center: CDF-S PI: Hans-Walter Rix, MPIA 10,000 galaxies, 17 filters (  m) Photo-redshifts  1.2  z ~ 0.02

15 The Evolution of Structure in the Universe The universe was smooth very early (t 500) Density fluctuations,  /  ~10 -5, seeded structure Little time to make 1 st stars before t~200 Myr 1 st stars collapsed without dust Massive stars t ~ 100 Myr Coalescence occurred ~few Gyr Gyr  vigorous buildup Cold Dark Matter (CDM) generally gives the right sense of growth Bottoms up vs. Top down: “hierarchical clustering” Era of combination: p + + e -  H 0  /  ~ Relaxed galaxies, stars, planets, life Galaxy assembly from pieces z t(Gyr) x H 0 =65  M =0.3   =0.7 Following CDM models (e.g. White et al.)

16 Gravitational Lensing & Dark Matter background galaxy large mass lensed image “true” image Mass Light  Dark matter

SN 1994d Brightness  1 Distance x Distance Hubble can see supernova to when the universe was only 30% of its present age, about 4 billion years Distance 2 Distance 1

18 Supernovae as standard candles SN97cj The CfA SN team: Schmidt, Riess, Kirshner, Garnavitch et al. z = 0.50 SN97cj

19 Hubble diagram showing acceleration Recession velocity / light speed Faintness Perlmutter et al. (1998) Calan/Tololo (Hamuy et al, A.J. 1996) Supernova Cosmology Project fainter farther away decelerating accelerating Recession velocity is proportional to distance

20 SN 1997ff and universal acceleration Adam Riess et al Velocity / light speed Relative faintness

21 Distant Supernovae & ACS SN 2002dd at v/c = 1.06 Discovery May 11, 2002 The ACS GTO Team: P.I. Holland Ford, Deputy Garth Illingworth, Zlatan Tsvetanov, John Blakeslee and Adam Riess

22 SN 2002dd infrared light curve Days relative to maximum 1.25  m magnitude: J Adam Riess, Stefano Casertano & collaborators using NICMOS

23 Measurement of universal acceleration Velocity / light speed Relative faintness

24 Composition of the Universe

25 NGC 3132: Planetary nebula SOME say the world will end in fire, Some say in ice. From what I’ve tasted of desire I hold with those who favor fire. But if it had to perish twice, I think I know enough of hate To know that for destruction ice Is also great And would suffice. Robert Frost Harper’s Magazine December 1920

Telescope Sensitivity & Discoveries Galileo Sensitivity Improvement over the Eye Year of observations Telescopes alone Photographic & electronic detection Huygens eyepiece Slow f ratios Short’s 21.5” Herschell’s 48” Rosse’s 72” Photography Mount Wilson 100”Mount Palomar 200”Russian 6-m After Fig in Cosmic Discovery, M. Harwit 10 CCDs Hubble Space Telescope Next Generation Space Telescope

Improving Hubble ACS (=10X WFPC2) WFC3 (=25X NICMOS) STIS (=40X Original Spectrographs) COS (=20X STIS) NICMOS/NCS SM2 SM3B SM4 WFPC2 SM1 NICMOS (1-2  m) Servicing Missions

The Distant Universe Steven Beckwith Presentation to the US Embassy, NZ July 8, 2002 The first galaxies seen from the Hubble Space Telescope