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

Technology drives the New Sky  Microelectronics  Software  Large Optics Fabrication

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

Relative Survey Power 15 sec exposures 2000 exposures per field

Large Synoptic Survey Telescope

The LSST optical design: three large mirrors

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

The LSST site 1.5m photometric calibration telescope

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

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

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

Large CCD mosaics

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

The LSST thick CCD Sensor 16 segments/CCD 200 CCDs total 3200 Total Outputs

LSST Project Cerro Pachón 2006 Site Selection Construction Proposals (NSF and DOE) Complete Engineering Construction 2015Commissioning Milestones and Schedule Partnership of government (NSF and DOE) and private support.

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.

The LSST Corporation has 21 members Brookhaven National Laboratory California Institute of Technology Columbia University Google, 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 University The University of Arizona University of California at Davis University of California at Irvine University of Illinois at Urbana-Champaign University of Pennsylvania University of Washington

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 Figure : Visits numbers per field for the 10 year simulated survey

Photometric Redshifts

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

LSST Science Charts New Territory Probing Dark Matter And Dark Energy Mapping the Milky Way Finding Near Earth Asteroids

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

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 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

Comparing HST with Subaru

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

Sloan Digital Sky Survey

Deep Lens Survey

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

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)

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

Distinguishing DE theories Zhan /

Dark Energy Precision vs time Combined Separate DE Probes

Mass in CL0024 LSST will constrain the nature of dark matter

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

LSST Science Collaborations 1.Supernovae: M. Wood-Vasey (CfA) 2.Weak lensing: D. Wittman (UCD) and B. Jain (Penn) 3.Stellar Populations: Abi Saha (NOAO) 4.Active Galactic Nuclei: Niel Brandt (Penn State) 5.Solar System: Steve Chesley (JPL) 6.Galaxies: Harry Ferguson (STScI) 7.Transients/variable stars: Shri Kulkarni (Caltech) 8.Large-scale Structure/BAO: Andrew Hamilton (Colorado) 9.Milky Way Structure: Connie Rockosi (UCSC) 10. Strong gravitational lensing: Phil Marshall (UCSB)

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

D LS DSDS  = 4GM/bc 2 b   D LS DSDS 4GM/bc 2 sheared image shear Gravity & Cosmology change the growth rate of mass structure Cosmology changes geometric distance factors

Cosmic shear vs redshift

Shear Tomography Shear spatial power spectra at redshifts to z  2. z  z  Needed shear sensitivity Linear regimeNon-linear regime ΛCDM Cosmology Fit Region

Residual shear correlation Cosmic shear signal 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) Stars

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

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