New Directions in Observational Cosmology: A New View of our Universe

1. New Directions in Observational Cosmology: A New View of our Universe Tony Tyson UC Davis Berkeley May 4, 2007

2. Technology drives the New Sky • Microelectronics • Software • Large Optics Fabrication

3. LSST Wide+Deep+Fast: Etendue Primary mirror diameter Field of view (full moon is 0.5 degrees) 0.2 degrees 10 m 3.5 degrees Keck Telescope

4. Relative Survey Power 15 sec exposures 2000 exposures per field

5. Large Synoptic Survey Telescope deep wide fast

6. The LSST optical design: three large mirrors

7. The telescope design is complete Camera and Secondary assembly Finite element analysis Carrousel dome Altitude over azimuth configuration

8. The LSST site 1.5m photometric calibration telescope

9. 3.2 gigapixel camera Raft Tower L3 Lens Shutter L1/L2 Housing Five Filters in stored location L1 Lens Camera Housing L2 Lens Filter in light path

10. Camera body with five filters and shutter Back Flange Filter Carousel Filter Changer rail Shutter Manual Changer access port Filter Changer

11. 2d Focal plane Sci CCD 40 mm The LSST Focal Plane Guide Sensors (8 locations) Wavefront Sensors (4 locations) Wavefront Sensor Layout Curvature Sensor Side View Configuration 3.5 degree Field of View (634 mm diameter)

12. Large CCD mosaics

13. 4Kx4K Si CCD Sensor CCD Carrier Thermal Strap(s) SENSOR basic building block: the raft tower 3 x 3 CCD Sensor Array Raft Assembly Flex Cable & Thermal Straps Electronics Cage Electronics RAFT TOWER

14. The LSST thick CCD Sensor 16 segments/CCD200 CCDs total3200 Total Outputs

15. LSST Project Partnership of government (NSF and DOE) and private support. Milestones and Schedule • Site Selection • Construction Proposals • (NSF and DOE) • 2007-2009 Complete Engineering • 2010-2015 Construction • 2015 Commissioning Cerro Pachón

16. The Data Challenge • ~2 Terabytes per hour that must be mined in real time. • More than 10 billion objects will be monitored for important variations in real time. • Knowledge extraction in real time.

17. The LSST Corporation has 21 members Brookhaven National Laboratory California Institute of TechnologyColumbia UniversityGoogle, Inc. Harvard-Smithsonian Center for Astrophysics  Johns Hopkins University  Kavli Institute for Particle Astrophysics and Cosmology - Stanford University Las Cumbres Observatory Global Telescope Network, Inc. Lawrence Livermore National Laboratory  National Optical Astronomy Observatory Princeton University Research Corporation Stanford Linear Accelerator Center  The Pennsylvania State University Purdue UniversityThe University of ArizonaUniversity of California at Davis University of California at Irvine University of Illinois at Urbana-Champaign  University of Pennsylvania University of Washington

18. Figure : Visits numbers per field for the 10 year simulated survey LSST imaging & operations simulations Sheared HDF raytraced + perturbation + atmosphere + wind + optics + pixel LSST Operations, including real weather data: coverage + depth Performance verification using Subaru 15 sec imaging

19. Photometric Redshifts

20. LSST survey of 20,000 sq deg • 4 billion galaxies with redshifts • Time domain: • 100,000 asteroids • 1 million supernovae • 1 million lenses • new phenomena

21. LSST Science Charts New Territory Probing Dark Matter And Dark Energy Mapping the Milky Way opens the time window! Finding Near Earth Asteroids

22. 3-D Mass Tomography 2x2 degree mass map from Deep Lens Survey

23. Resolving galaxies A given galaxy at high redshift should appear smaller. But two effects oppose this: cosmological angle-redshift relation, and greater star formation in the past (higher surface brightness). Here are plots of galaxy surface brightness vs radius (arcsec) in redshift bins from z = 0.5 – 3.0 for 23-25 apparent mag. At a surface brightness of 28 i mag/sq.arcsec (horizontal dashed line) most galaxies at z<3 are resolved in 0.6 arcsec FWHM seeing (vertical dashed line). HST/ACS GOODS, Ferguson 2007

24. Comparing HST with Subaru

25. Comparing HST with Subaru

26. DSS: digitized photographic plates One quarter the diameter of the moon

27. Sloan Digital Sky Survey

28. Deep Lens Survey

29. Massively Parallel Astrophysics • Dark matter/dark energy via weak lensing • Dark energy via baryon acoustic oscillations • Dark energy via supernovae • Galactic Structure encompassing local group • Dense astrometry over 20000 sq.deg: rare moving objects • Gamma Ray Bursts and transients to high redshift • Gravitational micro-lensing • Strong galaxy & cluster lensing: physics of dark matter • Multi-image lensed SN time delays: separate test of cosmology • Variable stars/galaxies: black hole accretion • QSO time delays vs z: independent test of dark energy • Optical bursters to 25 mag: the unknown • 5-band 27 mag photometric survey: unprecedented volume • Solar System Probes: Earth-crossing asteroids, Comets, TNOs

30. Key LSST Mission: Dark Energy Precision measurements of all four dark energy signatures in a single data set. Separately measure geometry and growth of dark matter structure vs cosmic time. • Weak gravitational lensing correlations + CMB (multiple lensing probes!) • Baryon acoustic oscillations (BAO) + CMB • Counts of dark matter clusters + CMB • Supernovae to redshift 1 (complementary to JDEM)

31. Critical Issues • WL shear reconstruction errors • Show control to better than required precision using existing new facilities • Photometric redshift errors • Develop robust photo-z calibration plan • Undertake world campaign for spectroscopy () • Photometry errors • Develop and test precision flux calibration technique

32. Distinguishing DE theories Zhan /0605696

33. Dark Energy Precision vs time Separate DE Probes Combined

34. Mass in CL0024 LSST will constrain the nature of dark matter

35. Mass in CL0024 LSST will measure total neutrino mass LSST WL+BAO+P(k) + Planck

36. LSST Science Collaborations • Supernovae: M. Wood-Vasey (CfA) • Weak lensing: D. Wittman (UCD) and B. Jain (Penn) • Stellar Populations: Abi Saha (NOAO) • Active Galactic Nuclei: Niel Brandt (Penn State) • Solar System: Steve Chesley (JPL) • Galaxies: Harry Ferguson (STScI) • Transients/variable stars: Shri Kulkarni (Caltech) • Large-scale Structure/BAO: Andrew Hamilton (Colorado) • Milky Way Structure: Connie Rockosi (UCSC) • Strong gravitational lensing: Phil Marshall (UCSB)

37. http://www.lsst.org

38. LSST Ranked High Priority • NRC Astronomy Decadal Survey • NRC New Frontiers in the Solar System • NRC Quarks-to-Cosmos • SAGENAP • Quantum Universe • Physics of the Universe • Dark Energy Task Force + P5

39. sheared image a = 4GM/bc2 b DS DLS q shear DLS g ~ q = 4GM/bc2 DS Gravity & Cosmology change the growth rate of mass structure Cosmology changes geometric distance factors

40. Cosmic shear vs redshift

41. z=3.2 ΛCDM 0.01 Needed shear sensitivity z=0.2 0.001 Cosmology Fit Region Linear regime Non-linear regime Shear Tomography Shear spatial power spectra at redshifts to z  2.

42. Residual shear correlation Test of shear systematics: Use faint stars as proxies for galaxies, and calculate the shear-shear correlation after correcting for PSF ellipticity via a different set of stars. Compare with expected cosmic shear signal. Conclusion: 200 exposures per sky patch will yield negligible PSF induced shear systematics. Wittman (2005) Cosmic shear signal Stars

43. Cosmic Microwave Backgound • Characteristic oscillations in the CMB power WMAP reveals a picture of the fireball at the moment of decoupling: redshift z = 1080 TemperaturePower   Angular scale

44. Baryon Acoustic Oscillations CMB (z = 1080) BAO (z < 3) RS~140 Mpc Standard Ruler Two Dimensions on the Sky Angular Diameter Distances Three Dimensions in Space-Time Hubble Parameter