1. DARK MATTER & GALACTIC ROTATION 2012 ASTRO SUMMER SCHOOL

3. In 1933, Fritz Zwicky calculated the mass of the Coma Cluster

4. More evidence was discovered by Vera Rubin who measured the rotation curves of many galaxies during the 1970s.

5. The expected distribution of dark matter in the Milky Way

6. Cosmic Microwave Background (CMBR)

7. CMBR Power Spectrum The first peak gives us information about the curvature of the Universe. The ratio of the odd peaks to the even peaks gives us the baryon density. The third peak tells us about the density of dark matter. We can alter the cosmological parameters so that the curve fits the observed data.

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9. Dark Matter – Then and Now

10. Gravitational Lensing

11. Abell 1689

12. LRG-3757

13. The Bullet Cluster

14. More evidence for dark matter Velocity dispersion of galaxies Measurements of the velocities of galaxies within clusters. Acoustic oscillations Periodic fluctuations in baryonic matter caused by acoustic waves in the early Universe. Type Ia supernovae measurements Put a limit on the amount of dark energy hence constrain dark matter Structure formation If the Big Bang model is correct, dark matter is required to allow structures to form.

15. Rotation curves

16. Galactic rotation curves

17. Cryogenic detector experiments Cryogenic detectors, operating at temperatures below 100mK, detect the heat produced when a particle hits an atom in a crystal absorber such as germanium. CDMSII, Soudan Mine, Minnesota CRESST, Gran Sasso, Italy

18. Noble liquid experiments Noble liquid detectors detect the flash of scintillation light produced by a particle collision in liquid xenon or argon. XENON, Gran Sasso, Italy DEAP, Ontario, Canada

19. Indirect detection methods Indirect detection experiments search for the products of WIMP annihilation. If WIMPs are Majorana particles (the particle and antiparticle are the same) then two WIMPs colliding could annihilate to produce gamma rays or particle-antiparticle pairs. This could produce a significant number of gamma rays, antiprotons or positrons in the galactic halo. The detection of such a signal is not conclusive evidence for dark matter, as the production of gamma rays from other sources are not fully understood. EGRET - Energetic Gamma Ray Experiment Telescope PAMELA - Payload for Antimatter Matter Exploration and Light-nuclei Astrophysics GLAST - Gamma-ray Large Area Space Telescope (also known as Fermi)