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Progress on Cosmology

Progress on Cosmology. Sarah Bridle University College London. Progress on Cosmology. Definition of “Cosmology” for this talk The latest observations 2.1 Type Ia supernovae 2.2 Galaxy clustering 2.3 Cosmic shear The future. Progress on Cosmology. Definition of “Cosmology” for this talk

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Progress on Cosmology

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  1. Progress on Cosmology Sarah Bridle University College London

  2. Progress on Cosmology • Definition of “Cosmology” for this talk • The latest observations 2.1 Type Ia supernovae 2.2 Galaxy clustering 2.3 Cosmic shear • The future

  3. Progress on Cosmology • Definition of “Cosmology” for this talk • The latest observations 2.1Type Ia supernovae 2.2 Galaxy clustering 2.3 Cosmic shear • The future

  4. My Definition of Observational Cosmology Telescope observations of the Universe aimed at measuring global parameters • Cosmic Microwave Background (CMB) • See talk by Francois Bouchet next • Large-scale structure of the Universe, especially • Galaxy clustering • Clusters of galaxies • Gravitational lensing • Standard candles e.g. Type Ia supernovae

  5. Concordance Model 74% Dark Energy 4% Baryonic Matter 22% Cold Dark Matter

  6. What Observational Cosmology Measures • Post-inflation conditions • Scalar, tensor (+other?) perturbation power spectra • The expansion rate (Hubble constant) • Baryonic matter density • Dark matter • density, distribution – as f(time) • Dark energy • density, distribution – as f(time) • Or modifications to GR (see de Rham talk on Friday)

  7. Big Bang 5 billion years ago Today Credit: Richard Massey, NASA

  8. Why is the Universe Accelerating? • Einstein’s cosmological constant • A new fluid called Dark Energy • Equation of state w=p/ • General Relativity is wrong

  9. Progress on Cosmology • Definition of “Cosmology” for this talk • The latest observations 2.1 Type Ia supernovae 2.2 Galaxy clustering 2.3 Cosmic shear • The future

  10. Latest Supernova Compilation Distance Dark Energy Equation of State w Distance – distance if no DE Matter Density Redshift Hicken et al 2009

  11. Progress on Cosmology • Definition of “Cosmology” for this talk • The latest observations 2.1 Type Ia supernovae 2.2 Galaxy clustering 2.3 Cosmic shear • The future

  12. Galaxy Clustering Constraints on Dark Energy Dark Energy Equation of State w 1-Matter Density Hicken et al 2009, showing results using Eisenstein et al 2005

  13. Neutrino Mass Constraints from Galaxy Clustering m Matter Density Thomas, Abdalla & Lahav 2010

  14. Progress on Cosmology • Definition of “Cosmology” for this talk • The latest observations 2.1 Type Ia supernovae 2.2 Galaxy clustering 2.3 Cosmic lensing • The future

  15. Gravitational Lensing

  16. Cosmic Lensing Tyson et al 2000

  17. Universe was 0.2 Gyr old Credit: Springel et al. (2005)

  18. Universe was 1 Gyr old Credit: Springel et al. (2005)

  19. Universe was 4.7 Gyrs old Credit: Springel et al. (2005)

  20. Today (13.6 Gyr) Credit: Springel et al. (2005)

  21. Results from the HST COSMOS Survey

  22. Progress on Cosmology • Definition of “Cosmology” for this talk • The latest observations 2.1 Type Ia supernovae 2.2 Galaxy clustering 2.3 Cosmic shear • The future

  23. The Future JDEM See Moniez talk on Friday

  24. Comparison of different methods Galaxy clustering Supernovae Gravitational shear Quality of dark energy constraint Example for optical ground-based surveys Dark Energy Task Force report Albrecht et al. astro-ph/0609591 Gravitational shear has the greatest potential Big uncertainty largely due to shear measurement techniques Maybe dark energy is the wrong model...

  25. Future prospects The Dark Energy Survey • Cosmic microwave background radiation • Distribution of dark matter at early times • Distribution of galaxies • Some clues to distribution of matter • Galaxy velocities • Galaxies fall towards dark matter clumps • Gravitational lensing

  26. C3 C1

  27. WideExtragalactic 20,000 deg2 Galactic Plane Deep ~40 deg2 • 20 000 sq deg RIZAB ≤ 24.5 at 0.16” FWHM,yielding 30-40 resolved galaxies/amin2,z~ 0.9 • NIR photometry: Y, J, H ≤ 24 (AB, 5σ PS). Spectroscopy. • Refregier et al Science Book arxiv:1001.0061

  28. HST COSMOS

  29. End

  30. Map in 3d

  31. The camera: DECam Mechanical Interface of DECam Project to the Blanco CCD Readout Focal plane (detector) Filters Shutter Hexapod Corrector Lenses

  32. Kowalski et al 2008

  33. space weak lensing shear ground Ground vs Space

  34. Larson et al 2010, WMAP7

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