The complete history of the Universe (abridged)The Big BangThe Big Bang

and theand the

Cosmic Microwave Cosmic Microwave BackgroundBackground

(With thanks to Angela Taylor) Sutton Trust Summer School 2005

Keith Grainge

The Hubble Deep Field

Optical Spectra Optical Spectra

Atoms and molecules absorb and emit at Atoms and molecules absorb and emit at particular frequencies particular frequencies line spectra. line spectra.

Can learn temperature, density, and Can learn temperature, density, and chemical composition.chemical composition.

Also velocity …Also velocity …

The Doppler Effect for EM The Doppler Effect for EM radiationradiation

Hubble, law

Hubble’s Law

Hubble’s Data (1929)

v = H0d

recession Hubble distance velocity constant

Expansion of the UniverseExpansion of the Universe

(Wayne Hu’s web page: background.uchicago.edu/~whu)

Evolution of the UniverseEvolution of the Universe4

3

2

1

0

Age of Universe (Billion years)

Rel

ativ

e si

ze o

f U

niv

erse

Flat Universe

‘Big Crunch’

AcceleratingUniverse

-10 Now 10 20 30

Ingredients of the UniverseIngredients of the Universe

RadiationRadiation

Dark MatterDark Matter

Ordinary matterOrdinary matter

Dark EnergyDark Energy

Geometry of the UniverseGeometry of the Universe

‘Positively’ curved

‘Negatively’ curved

Flat

The Cosmic Microwave The Cosmic Microwave BackgroundBackground

The background is the left over radiation from the Big Bang. It The background is the left over radiation from the Big Bang. It has now cooled to a temperature of 2.7 Khas now cooled to a temperature of 2.7 K

The Cosmic Microwave The Cosmic Microwave BackgroundBackground

Imprint in the background due to the motion of the Earth, about Imprint in the background due to the motion of the Earth, about 1 part in 1,000 of the total intensity1 part in 1,000 of the total intensity

The Cosmic Microwave The Cosmic Microwave BackgroundBackground

The ripples in the background correspond to only about one part The ripples in the background correspond to only about one part in 100,000 of the total intensityin 100,000 of the total intensity

Map of Sky Power Spectrum

Power

Power

Power

1/Angular Size

1/Angular Size

1/Angular Size

GROUND BASEDGROUND BASED

INSTRUMENTS …INSTRUMENTS …

FLYING FROM BALLOONS …FLYING FROM BALLOONS …

PLANCK - 2007 WMAP – flying now

SATELLITE MISSIONS SATELLITE MISSIONS

The Very Small ArrayThe Very Small Array

Observatorio del Teide, TenerifeObservatorio del Teide, Tenerife

VSA RESULTS – Jan 2004VSA RESULTS – Jan 2004

VSA Power SpectrumVSA Power Spectrum

WMAP Power Spectrum(P

ow

er)

(1/Angle on sky)

The Age of the Universe …The Age of the Universe …

13.7 Billion Years

Geometry of the Universe …Geometry of the Universe …

FLAT

Ingredients of the Universe Ingredients of the Universe ……

The local Universe - Galaxies The local Universe - Galaxies

Spiral Galaxy M63Spiral Galaxy M63

If this were our Galaxy, ourIf this were our Galaxy, ourSun would be located about hereSun would be located about here

The Universe on the Largest The Universe on the Largest Scale - the Cambridge APM Scale - the Cambridge APM

survey survey

Over 2 million galaxies in direction of the South Galactic Over 2 million galaxies in direction of the South Galactic pole. The map covers about one tenth of the skypole. The map covers about one tenth of the sky

Structure FormationStructure Formation

(Simulation and movie courtesy of Andrey Kravtsov)(Simulation and movie courtesy of Andrey Kravtsov)

Interacting Galaxies Interacting Galaxies

Interacting Galaxies Interacting Galaxies

HST image of colliding galaxies NGC 4038 and NGC 4039HST image of colliding galaxies NGC 4038 and NGC 4039

SummarySummary

After the Big Bang the Universe was After the Big Bang the Universe was hot and smooth. hot and smooth.

As it expanded it cooled.As it expanded it cooled. The CMB is a picture of the Universe The CMB is a picture of the Universe

when it was only 300,000 years old.when it was only 300,000 years old. Under the influence of gravity Under the influence of gravity

structure has formed.structure has formed.