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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
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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
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Astronomy Scales 1 pc = 3 light years = 3 1016 km Nearest Stars
Nearest Galaxies Nearest Galaxy Clusters 4.5 pc 450 kpc 150 Mpc
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Galaxies Spiral (Milky Way) Solar Mass: M = 2 1033g
1kpc 1kpc ~ 10% mass Solar Mass: M = g Typical stars mass 1-10 M Typical Galaxies M 100kpc
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Milky Way Galaxy Magnetic field few G
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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
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Active Galactic Nuclei
Radio Images Visible light
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QUASARS & MICROQUASARS
QUASAR MICROQUASAR QUASAR MICROQUASAR Central black hole M M distant galaxies local galaxy
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QUASARS & MICROQUASARS
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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
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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
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Multi-Messengers to see Whole Universe
Distant universe invisible in high energy photons need neutrinos Quasar formation period
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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
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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
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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
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Future of Universe
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Origin of Elements formed in: Big Bang Nucleo-synthesis Hot Stars
Supernova Explosions Cosmic Ray Interactions
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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
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Particle Physics after Big Bang
time since Big Bang
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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
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Nucleosynthesis starts
Deuterium necessary to start nucleosynthesis Helium formed from deuterium ( Difficult to continue because no stable mass 5, 8 nuclei)
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Nucleosynthesis development
helium-4 deuterium helium-3 tritium (free neutrons decay) Be, Li low levels
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Element Production in Stars
PP cycle : cold stars CNO cycle : hot stars
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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
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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
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End of Opaque Universe After recombination universe becomes transparent. See photons as Cosmic Microwave Background Radiation redshifted by 1000 to 2.7K
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Penzas and Wilson Discovery of Cosmic Microwave Background
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Cosmic Microwave Background Radiation
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Cosmic Microwave Background Radiation
temperature variation -30 -35 -40 -45 -50 -55 -60 (degrees) (degrees) Analyse angular distribution to see typical variation scale
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Measure Scale of CMBR Fluctuations
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CMBR Data Analysis location of first peak: Wtotal ~ 1
amplitude of other peaks sensitive to Wbaryon
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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
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SuperNovae observed in our galaxy
Date Remnant Observed 352 BC Chinese 185 AD SNR Chinese 369 ? Chinese Chinese SNR Chinese 437 ? 827 ? 902 ? SN Arabic, ... Crab Chinese,.. C Chinese,.. 1203 ? 1230 ? Tycho Tycho Brahe Kepler Johannes Kepler Cas A not seen ?
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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
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Supernova in Large Magellenic Cloud
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Distant Supernova
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Life of big star ( > 1,4 M)
End in Supernovae of type Ib, Ic et II
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Life of big star ( < 1,4 M)
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La nébuleuse de la Lyre
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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
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Reference Image Subtraction
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Expansion with Supernova Ia
Acceleration of universe expansion effective magnitude brightness distance non-linear v = H(t) d redshift recession velocity
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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
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So what does it mean? ( due to E. Copeland, a theorist)
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Supernova at z1.7
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Future Project: SNAP 2500 SNe Ia per year with z < 1.7
Study Equation of state w=pw/w - -
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Understanding Nature of Dark Energy
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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 km/s/Mpc M = matter critical
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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
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