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Lecture 26. updates. Evidence for an Evolving Universe Made in a Hot Big Bang. Galaxy redshifts expansion, which started ~14 Byr ago Age measurements nothing older than 12-15 Byr Distant galaxies appear younger contents are aging
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Lecture 26 updates
Evidence for an Evolving Universe Made in a Hot Big Bang Galaxy redshifts expansion, which started ~14 Byr ago Age measurements nothing older than 12-15 Byr Distant galaxies appear younger contents are aging CMB is uniform and thermal hot smooth early phase CMB is patchy yields patterns of galaxies 25% helium made in Hot Big Bang itself
3H02 8G crit = Omegas de = 0.73 dm = 0.23 at = 0.04 rad = 5.010-5 nu = 3.410-5 tot = 1.00 Primary Cosmological Parameters Hubble’s constant: today’s expansion rate H0 = 22 km/s/Mly = 5.8 mH/m3 Constituent densities (units of mH/m3) de = 4.2 dark energy dm = 1.6 dark matter at = 0.25 atomic matter rad = 0.00029 photons nu = 0.00017 neutrinos tot = 5.8 total density
Initial roughness spectrum 200 Mly Amplitude Slope: n A Amplitude: A Small Large Size Primary Cosmological Parameters The Roughness Spectrum Today’s roughness spectrum Amplitude Large Small Size
Primary Cosmological Parameters Dark energy expansion parameter: w Measured value: w≈ 1
H0 = 22 km/s/Mly The Five Key Datasets 1. Distances to Nearby Galaxies 30,000 20,000 Velocity (km/s) 10,000 0 400 200 300 0 100 Distance (Mpc)
The Five Key Datasets 2. Distances to Remote Galaxies using Supernovae remote galaxy supernova
m = 0 de = 0 m = 1 de= 0 Supernova data m = 8 de = 0 m = 0.3 de= 0.7 Supernova data give S(t) S(t) depends on: de and m Scale Factor: S 1 Now 0 10 10 Time (Byr)
WMAP Satellite Uniform microwave sky The Five key datasets 3. The Microwave Background Two images present
Frequency (GHz) 300 450 150 1.0 Brightness 0.5 0.0 4.0 2.0 1.0 0.5 Wavelength (mm) The Five key datasets 3. The Microwave Background Thermal Spectrum TCMB = 2.725 K rad
Slight Patchiness The Five key datasets 3. The Microwave Background Two images present
CMB Sound Spectrum fundamental harmonics instruments . data model Patch size (degrees) Patch Strength (Loudness) Small Patches Big Patches Curly “ell” Frequency ( l )
Sound Spectrum Sensitivity instruments . data model Patch size (degrees) tot at Patch Strength (Loudness) m Small Patches Big Patches Curly “ell” Frequency ( l )
Effect of Changing Atomic Fraction at = 0.1 10% atomic matter Amplitude small scale large scale Angular Frequency l at = 0.01 1% atomic matter
Fitting the Sound Spectrum m = 0.27 de = 0.73 10 m = 0.27 de = 0.0 3 Amplitude 1 10 1000 100 Angular Frequency l
1 Bly Real galaxy maps 2 Bly 2 Bly Millennium simulation 1 Bly
m = 0.30 Baryon Oscillations Galaxy roughness spectrum 10 m = 0.42 1 m = 0.14 Roughness Amplitude 0.1 0.01 1 Large Scale 0.1 0.01 Small Scale Scale of Roughness
The Five Key Datasets 5: Abundances of the Light Elements Deuterium Helium-3 Helium-4 Lithium-7
0.001 0.01 1 0.1 at = 0.04 Omega-atomic (today) 1.0 He-4 10-2 D He-3 10-4 Fraction by mass 10-6 10-8 Li-7 10-10 100 1 10 Proton + Neutron Density (gm/m3 at 3 minutes)
Combining datasets 2 Supernovae Combined Data 1 CMB Omega-dark energy 0 Clusters 1 2 3 0 1 Omega-matter
CMB sound spectrum Amplitude Frequency at = 0.04 Matter roughness Roughness Large Scale/Size Small
20 15 Age of Universe (Byr) 10 5 0 0.8 1.0 1.2 1.4 Total Density tot
Ruled out by WMAP First Year Allowed
Ruled out by WMAP First Year Allowed Ruled out by WMAP 3 Years
Ruled out by WMAP First Year Allowed Ruled out by WMAP 3 Years Ruled out by Redshift Surveys
Ruled out by WMAP First Year Allowed Ruled out by WMAP 3 Years Ruled out by Redshift Surveys Ruled out by Stellar ages
End of Lecture text
Supernova data give S(t) m = 0 de = 0 S(t) curves depend on de and mat m = 1 de= 0 m = 0.3 de= 0.7 Label y-axis with scale factor m = 8 de = 0 Need version of this diagram