Post on 31-Mar-2015
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.