Neutrino Ocillations and Astroparticle Physics (3) John Carr Centre de Physique des Particules de Marseille (IN2P3/CNRS) Pisa, 8 May 2002 Introduction to Cosmology and High Energy Astronomy - expansion of the universe - some astronomy - some cosmology - big bang nucleosynthesis - cosmic microwave background radiation - SuperNova Type 1a - Energy composition of universe
Expansion of Universe v= H r H ~ 70 km/sec / Mpc Velocity of galaxy Edwin Hubble Mt. Wilson 100 Inch Telescope Velocity of galaxy proportional to distance: v= H r H ~ 70 km/sec / Mpc
Astronomy Scales 1 pc = 3 light years = 3 1016 km Nearest Stars Nearest Galaxies Nearest Galaxy Clusters 4.5 pc 450 kpc 150 Mpc
Galaxies Spiral (Milky Way) Solar Mass: M = 2 1033g 1kpc 1kpc ~ 10% mass Solar Mass: M = 2 1033g Typical stars mass 1-10 M Typical Galaxies 106 - 1012 M 100kpc
Milky Way Galaxy Magnetic field few G
Cosmic Accelerators: Hillas Plot Crab Pulsar E Z B L B Z: Charge of particle B: Magnetic field L: Size of object : Lorentz factor of shock wave M87, AGN Centurus A GRB (artist) 3C47 Vela SNR L
Active Galactic Nuclei Radio Images Visible light
QUASARS & MICROQUASARS QUASAR MICROQUASAR QUASAR MICROQUASAR Central black hole 108- 109 M 102- 105 M distant galaxies local galaxy
QUASARS & MICROQUASARS
Gamma-Ray Burst Story Gamma Ray Burst were first detected by the Vela satellites that were developed in the sixties to monitor nuclear test ban treaties. 1st GRB
Gamma Ray Bursts : present knowledge ~1-2 / day, duration 10ms - 100s, isotropic distribution in sky, at extra galactic distances. Count rate in unit of 1000 counts s-1 Now evidence of GRB association with supernova sec ANTARES will dump all data in 100 secs of gamma ray burst warning signal
Multi-Messengers to see Whole Universe Distant universe invisible in high energy photons need neutrinos Quasar formation period
Evolution of the Universe Consider a particle on surface of sphere which expands with universe: r : radius of sphere Mass inside sphere is: (4/3) r3 Potential energy of particle: -(4/3)r3 G/r Kinetic energy: r2/2 so total energy: r2/2 -(4/3)r3 G/r = E : mass density in universe . . Sphere evolves with time, write r(t) = a(t) x remember H = v/r = a/a . Then get Freidmann equation: H2 = (8/3) G - K/a2 where K = -2E Evolution of universe depends on value of K if K < 0, energy E > 0 expansion continues for ever if K > 0, energy E < 0 eventually universe contracts K = 0 critical value
Matter Density and Curvature of the Universe Freidmann eqn: H2 = (8/3) G - K/a2 With K = 0 Freidmann equation: H2 = (8/3) G define critical density: c = (3/8)H2/G define density fraction: = / c Same K comes into the spatial line element in General Relativity: If K = 0, geometry is Euclidean - flat, if K = 0, geometry curved equivalently if = 0 universe is flat > 0 curvature positive, universe is closed < 0 curvature negative, universe is open
Cosmological Constant Einstein did not know about the expansion of the universe and add a ad-hoc term to make universe static Freidmann equation becomes: H2 = (8/3) G - K/a2 + /3 where is cosmological constant Theory no longer needs it, but experiment seems to indicate its presence Conventional to treat it as another contribution to the density fraction (t) = matter(t) + = matter +
Future of Universe
Origin of Elements formed in: Big Bang Nucleo-synthesis Hot Stars Supernova Explosions Cosmic Ray Interactions
Big Bang T (K) ~ 1010/t½ (s) temperature of universe 1010 K 3000 K Equilibrium n/p ends Nucleosynthesis begins 1010 K Neutral hydrogen forms universe transparent to light fossil photon radiation frozen temperature of universe 3000 K nuclei atoms 100 s 3 105 y time after big bang
Particle Physics after Big Bang time since Big Bang
First Minute after Big Bang Production rates = Annihilation rates equilibrium of particles and no nuclei formed N (neutron) N (proton) = e m/kT (m = 1.3 MeV) In equilibrium: When temperature falls below 1010 K (1 MeV) reactions cease
Nucleosynthesis starts Deuterium necessary to start nucleosynthesis Helium formed from deuterium ( Difficult to continue because no stable mass 5, 8 nuclei)
Nucleosynthesis development helium-4 deuterium helium-3 tritium (free neutrons decay) Be, Li low levels
Element Production in Stars PP cycle : cold stars CNO cycle : hot stars
Heavy Element Production in Supernova CNO cycle : hot stars rp process : supernova explosions rp process protons stable nuclei neutrons Nuclear cross-sections not well known: need accelerator measurements
Nucleosynthesis rate gives baryon density Measured abundance of He, D Fraction of baryons < 5% Must have non-baryonic particle dark matter = Nb/N , baryon number fraction
End of Opaque Universe After recombination universe becomes transparent. See photons as Cosmic Microwave Background Radiation redshifted by 1000 to 2.7K
Penzas and Wilson Discovery of Cosmic Microwave Background
Cosmic Microwave Background Radiation
Cosmic Microwave Background Radiation temperature variation -30 -35 -40 -45 -50 -55 -60 (degrees) 30 45 60 75 90 105 120 135 (degrees) Analyse angular distribution to see typical variation scale
Measure Scale of CMBR Fluctuations
CMBR Data Analysis location of first peak: Wtotal ~ 1 amplitude of other peaks sensitive to Wbaryon
Supernova Type 1a Implosion of core of red giant Expansion of matter shock wave 0.5 c Explosion of star Supernova Supernova Remnant SNIa occurs at Chandrasekar mass, 1.4 Msun ‘Standard Candle’ measure brightness distance: B = L / 4pd2 measure host galaxy redshift get recession velocity test Hubble’s Law: v = H d, at large distances
SuperNovae observed in our galaxy Date Remnant Observed 352 BC Chinese 185 AD SNR 185 Chinese 369 ? Chinese 386 Chinese 393 SNR 393 Chinese 437 ? 827 ? 902 ? 1006 SN1006 Arabic, ... 1054 Crab Chinese,.. 1181 3C58 Chinese,.. 1203 ? 1230 ? 1572 Tycho Tycho Brahe 1604 Kepler Johannes Kepler 1667 Cas A not seen ?
SuperNovae Remnants Crab Vela Kepler Tycho Cas A Cygnus Crab Tycho Soleil Vela Cas A Cygnus Loop Kepler SN1006 Tycho Cas A SN1006 SN1054 (Crab) SN1680 (CasA) Cygnus SN1006
Supernova in Large Magellenic Cloud
Distant Supernova
Life of big star ( > 1,4 M) End in Supernovae of type Ib, Ic et II
Life of big star ( < 1,4 M)
La nébuleuse de la Lyre
Type Ia supernovae SNe Ia sont which accrete matter from neighbour star in binary system When the mass achieves the Chandrasekhar mass (~1.4 M) star collapses to neutron star in supernova explosion. Red Giant Flow of matter White Dwarf Always same mass so always same luminosity Standard Candle for measuring universe expansion
Reference Image Subtraction
Expansion with Supernova Ia Acceleration of universe expansion effective magnitude brightness distance non-linear v = H(t) d redshift recession velocity
In 1998, two teams: High-Z Supernovae and Supernovae Cosmology Project simultaneously annouce non-zero cosmological constant: WL = 0,72 ± 0,23 WM = 0,28 ± 0,09
So what does it mean? ( due to E. Copeland, a theorist)
Supernova at z1.7
Future Project: SNAP 2500 SNe Ia per year with z < 1.7 Study Equation of state w=pw/w - -
Understanding Nature of Dark Energy
Evidence for Matter Density Combined Data Cosmic Microwave Background Radiation, Supernova 1a, Galaxy clusters and BBN tot = total critical critical density for flat universe critical= 3H2/8GN H = h . 100 km/s/Mpc M = matter critical
Matter/Energy in the Universe Wtotal = WM + WL 1 matter dark energy Matter: WM = Wb + W + WCDM 0.4 baryons neutrinos cold dark matter Baryonic matter : Wb ~ 0.05 stars, gas, brown dwarfs, white dwarfs Neutrinos: W ~ 0.003 if M(n) ~ 0.1 eV as from oscillations Cold Dark Matter : WCDM 0.3 WIMPS/neutralinos, axions