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Status of Cosmology Talk presented at the Topics in Astroparticle and Underground Physics (TAUP 2001) Conference Wendy L. Freedman Carnegie Observatories

Status of Cosmology

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Status of Cosmology. Talk presented at the Topics in Astroparticle and Underground Physics (TAUP 2001) Conference Wendy L. Freedman Carnegie Observatories. STATUS OF COSMOLOGY. Cosmological Parameters. H 0 W 0 W 0 = W m + W L + W k W m W L - PowerPoint PPT Presentation

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Page 1: Status of Cosmology

Status of Cosmology

Talk presented at the Topics in Astroparticle and Underground Physics (TAUP 2001) Conference

Wendy L. FreedmanCarnegie Observatories

Page 2: Status of Cosmology

Cosmological Parameters

H0

= m + + k

m

t0 Age = f(H0,m,)

EBL

STATUS OF COSMOLOGY

Page 3: Status of Cosmology

Assumptions

• Homogeneity and isotropy

• General relativity

• Hot big bang

Page 4: Status of Cosmology

Hubble (1929)

Local Group: ~ 1 Mpc Supernovae: ~400 Mpc Virgo cluster: ~15 Mpc Hubble radius:~3000h-1 Mpc

1 pc = 3.26 light years

Page 5: Status of Cosmology

Hubble H0 Key Project (2001)

Freedman et al. (2001), Ap.J.

1st tick mark

Hubble (1929)

Page 6: Status of Cosmology

Homogeneity and Isotropy

LocalLas Campanas Redshift SurveyCfA Redshift

Survey

Page 7: Status of Cosmology

Homogeneity and Isotropy

Anglo Australian Redshift Survey March, 2001

COBE map

Page 8: Status of Cosmology

Power Spectrum

m h1.00 0.250.35 0.70

~ mh ~ 0.25 0.05

Guzzo(2001)

Lineweaver, 1998

Page 9: Status of Cosmology

CMB Anisotropies

• Robust measure of 0 • Large degeneracies Hu, Sugiyama & Silk (1995), Lineweaver (2001)

H0=70

Page 10: Status of Cosmology

CMB Anisotropies: Netterfield et al. (2001)

Page 11: Status of Cosmology

mCurrent evidence:

Galaxy kinematics Cluster baryons

• fb ~ 10-20%• b h2 = 0.02• m ~ 0.3-0.4

X-ray gas Lensing

m ~ 0.3

Page 12: Status of Cosmology

Limits: e.g. Carroll, Press & Turner 1992

• Negative : For m <1, t0 > 10 Gyr, H0>40

> -7, • Positive :

For m <1, H0 < 100, high-z objects

< 2, • RECALL: (Planck scale)

> -2 x 10-29 g/cm-3

< 4 x 10-29 g/cm-3

vac ~ 1092 g/cm-3

•“only” ~1060 discrepancy (electroweak)

Page 13: Status of Cosmology

Type Ia supernovae + CMB constraintsm = 0.3, =0.7

•Riess et al. 1998 Perlmutter et al. 1998

Page 14: Status of Cosmology

Carroll Lambda plot

Carroll (2001)

i

Evolution of density parameters in the universe

Current values:m = 0.3, =0.7, r = 5 x 10-5

•Current epoch special•Very brief interval where m and comparable.

Timing Coincidence

Page 15: Status of Cosmology

• Infrared observations of supernovae:• Advantages: - dust Hamuy, Krisciunas, Phillips, Freedman, et al.

- chemical composition

•UBVRIJHK observations• H0

Hamuy et al. (2001)

Page 16: Status of Cosmology

Direct Measure of the Expansion Rate

Loeb (1998) : Lyman alpha clouds

•~2 m/s/CENTURY!• not yet feasible

Freedman (2001)

Page 17: Status of Cosmology

Evolution of the Fine Structure Constant

• Webb et al.

astro-ph/

0012539

Page 18: Status of Cosmology

t0 : The Age of the Universe

• white dwarf cooling

• nucleocosmochronology

• globular cluster evolution

Page 19: Status of Cosmology

t0

• First measurement of stellar uraniumU/Th

Cayrel (2001)

t0 = 12.6 3 Gyr

Biggest uncertainty:production ratios

Page 20: Status of Cosmology

t0

• Globular clusters

Chaboyer (2001)

t0=13.5 2 Gyr

Biggest uncertainty: DISTANCE SCALE

Page 21: Status of Cosmology

H0

• Distance Scale

• Gravitational lens time delays

• Sunyaev-Zel’dovich effect

Page 22: Status of Cosmology

H0 Key Project• Discovery of Cepheids using HST

• Intercompare several distance methods

• Tests for systematic errors

• Goal: H0 to 10%

Freedman et al. 1994

Page 23: Status of Cosmology

Progress in Distance Scale

M33 M31

, HST

= 5 log d (pc) - 5

VRIB

Page 24: Status of Cosmology

M100

M100 – HST

WFPC2 image

Virgo cluster galaxy

Page 25: Status of Cosmology

SN 1994DCepheids

Supernovae,

Tully-Fisher,

etc.

Page 26: Status of Cosmology

Key Project Results

Freedman et al. (2001), ApJ astro-ph/0012376

Page 27: Status of Cosmology

Key Project Results (2)

Freedman et al. (2001)

H0 = 72 3 (stat.) 7 (sys.) km/sec/Mpc

Largest uncertainties:Local distance scale, HST calibration

Page 28: Status of Cosmology

Expansion Ages

H0 =70 m

t0 (Gyr)

Open 0.2 0 12 1

Open 0.3 0

11 1

Flat 0.2 0.8 15 1.5

Flat 0.3 0.7 13.5 1.5

Flat 1.0 0 9 1

o

Page 29: Status of Cosmology

Gravitational LensingDdDds 2

2 Dsct = (1+zd)

Refsdal 1964, 1966

• ~6 time delays measured• H0 ~ 60 – 70 km/sec/Mpc• systematics ~20-30% level• dark matter distribution unknown => model dependence/degeneracy with H0

Page 30: Status of Cosmology

Sunyaev-Zel’dovich Effect

• 33 clusters

• H0 = 63 3 (statistical)

30% (systematic) • Carlstrom et al. (2001)

Birkinshaw (1999)

Page 31: Status of Cosmology

Extragalactic Background Light

• Olber’s paradox• Star formation history of universe• Baryonic mass processed in stars• Metal production in the universe

IEBL

(m)

NOTE: optical + IR background light = ~10% of that in CMB ~100 nW/m2/sr

Page 32: Status of Cosmology

Star Formation History of Universe

Steidel et al. (1998)

Galaxy Number CountsStar Formation Rate

• Slope of luminosity

function < 0.4 (converges)• (1+z)4 surface brightness

dimming severe problem

Page 33: Status of Cosmology

Redshifting M51 and M101

Kuchinski, Freedman, Madore & Trewhella (2001)

•At progressively

higher z, start

to lose even the

brightest galaxies

•Distant surveys

very incomplete1500 A

z~1 z~2

z~3 z~4

Page 34: Status of Cosmology

Difficulty of Measuring the EBL

• The optical EBL is faint!• Terrestrial airglow and zodiacal light dominate.

HST

Bernstein, Freedman & Madore (2001)

Page 35: Status of Cosmology

Total EBL • Total EBL

0.1 to 1000 m:

Bernstein, Freedman & Madore (2001)

U V I

HST IRASCOBE:DIRBEFIRAS

EBL (0.1 to 1000 m)

100 35 nWm-2sr-1

•~30% of light from stellar nucleosynthesis reradiated by dust

Page 36: Status of Cosmology

EBL Results

• The integrated background light is ~2x greater than

accounted for by galaxies detected individually.

• The spectral distribution of the background light is

similar to that of ordinary galaxies.

• No new exotic population of objects is required

(~60% undetected galaxies, ~30% missing light

from detected galaxies).

• The mass associated with starlight contributes ~1%

of the critical density.

• The metal production and star formation rate in the

universe has been underestimated by a factor of ~2.

Page 37: Status of Cosmology

Summary of Cosmological Parameters

H072 8 km/sec/Mpc (rms)

0 1.03 0.06

m 0.3 0.1

0.7 0.3

t0 13 2 Gyr

h0t0 0.96 0.13

EBL/ crit 0.011 0.004