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The Large Synoptic Survey Telescope Status Summary

The Large Synoptic Survey Telescope Status Summary. Steven M. Kahn SLAC/KIPAC. LSST Technical Concept. 8.4 Meter Primary Aperture 3.4 M Secondary 5.0 M Tertiary 3.5 degree Field Of View 3 Gigapixel Camera 4k x 4k CCD Baseline 65 cm Diameter 30 Second Cadence Highly Dynamic Structure

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The Large Synoptic Survey Telescope Status Summary

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  1. The Large Synoptic Survey Telescope Status Summary Steven M. Kahn SLAC/KIPAC

  2. LSSTTechnical Concept • 8.4 Meter Primary Aperture • 3.4 M Secondary • 5.0 M Tertiary • 3.5 degree Field Of View • 3 Gigapixel Camera • 4k x 4k CCD Baseline • 65 cm Diameter • 30 Second Cadence • Highly Dynamic Structure • Two 15 second Exposures • Data Storage and Pipelines Included in Project

  3. LSST Why is the LSST unique? 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

  5. The Essence of LSST is Deep, Wide, Fast! • Dark matter/dark energy via weak lensing • Dark matter/dark energy via supernovae • Galactic Structure encompassing local group • Dense astrometry over 30,000 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

  6. Principle LSST Science Missions • Dark Energy / Matter • Weak lensing - PSF Shape/ Depth / Area • Super Novae + Photo z – Filters / • Map of Solar System Bodies • NEA – Cadence • KBO - • Optical Transients and Time Domain • GRB Afterglows – Image Differencing • Unknown transients - • Assembly of the Galaxy and Solar Neighborhood • Galactic Halo Structure and Streams from proper motions • Parallax to 200pc below H-burning limit

  7. LSST and Dark Energy • LSST will measure 250,000 resolved high-redshift galaxies per square degree! The full survey will cover 18,000 square degrees. • Each galaxy will be moved on the sky and slightly distorted due to lensing by intervening dark matter. Using photometric redshifts, we can determine the shear as a function of z. • Measurements of weak lensing shear over a sufficient volume can determine DE parameters through constraints on the expansion history of the universe and the growth of structure with cosmic time.

  8. Color-redshift

  9. Cosmological Constraints from Weak Lensing Shear Underlying physics is extremely simple General Relativity: FRW Universe plus the deflection formula. Any uncertainty in predictions arises from (in)ability to predict the mass distribution of the Universe Method 1:Operate on large scales in (nearly) linear regime. Predictions are as good as for CMB. Only "messy astrophysics" is to know redshift distribution of sources, which is measurable using photo-z’s. Method 2:Operate in non-linear, non-Gaussian regime. Applies to shear correlations at small angle. Predictions require N-body calculations, but to ~1% level are dark-matter dominated and hence purely gravitational and calculable with foreseeable resources. Hybrids:Combine CMB and weak lens shear vs redshift data. Cross correlations on all scales.

  10. Measurement of the Cosmic Shear Power Spectrum • A key probe of DE comes from the correlation in the shear in various redshift bins over wide angles. • Using photo-z’s to characterize the lensing signal improves the results dramatically over 2D projected power spectra (Hu and Keeton 2002). • A large collecting area and a survey over a very large region of sky is required to reach the necessary statistical precision. • Independent constraints come from measuring higher moment correlations, like the 3-point functions. • LSST has the appropriate etendue for such a survey. From Takada et al. (2005)

  11. Constraints on DE Parameters From Takada et al. (2005)

  12. LSST Optical Design Optical Design 0.6”

  13. LSST Camera

  14. Camera Mechanical Layout L1 L2 Shutter L3 1.6m Detector array Filter

  15. Focal plane array 3.5° FOV  64 cm  Strawman CCD layout 4K x 4K, 10 µm pixels 32 output ports 201 CCDs total Raft = 9 CCDs + 1cm x 1cm reservedfor wavefront sensors

  16. LSST Data Management Infrastructure

  17. LSST Partners • Research Corporation • U of Arizona • National Optical Astronomical Observatory • U. of Washington • Stanford U. • Harvard-Smithsonian • U. of Illinois • U of California – Davis • Lawrence Livermore National Lab • Stanford Linear Accelerator Center • Brookhaven National Lab • Johns Hopkins University

  18. LSSTC Board of Directors John Schaefer, President LSST Director Anthony Tyson Steven Kahn, DeputyProject Manager Donald Sweeney Victor Krabbendam, Deputy Science Advisory Committee (SAC) System Scientist & Chair of Science Council Zeljko Ivezic System Engineering William Althouse Science Working Groups Education & Public Outreach Suzanne Jacoby Simulations Department Phil Pinto Camera Steven Kahn, Sci. Krik Gilmore, Mgr. Telescope/Site Charles Claver, Sci. Victor Krabbendam, Mgr. Data Management Timothy Axelrod, Sci. Jeffrey Kantor, Mgr. LSST Project Structure

  19. LSST CAMERA ORGANIZATION CHART ______________________________________________

  20. SLAC Participation in LSST • Faculty: Blandford, Burke, Kahn, Perl, Schindler • Physics Staff: Gilmore, Kim, Lee, S. Marshall, Rasmussen • Postdoctoral: Bradac, P. Marshall, Peterson • Engring/Tech: Althouse, Hodgson, Rogers, Thurston • Computing: Becla, Hanushevsky, Luitz

  21. Proposed Funding Model for the LSST • Concept and Development Phase (2004 – 2008) • $15M from LSSTC members and private sponsors • $15M from the NSF • $18M from the DOE • Construction Phase (2008 – 2013) • $120M from the NSF • $100M from the DOE • $50M from private sponsors • Operations Phase (2013 – 2023) • ~$20M/year is estimated as total annual operations budget ($10M/yr for the observatory and $10M/yr for data management)

  22. x x x x x Proposed funding and management configuration DOE LSSTC Private NSF Funding Sources LSST Collaboration Institutions LSSTC PMO SLAC BNL LLNL NOAO NCSA LSSTC Staff Universities Potential relationships established by MoA's Universities PMO: Program Management Office

  23. Key R&D Issues • Telescope • Implementation of the wavefront sensor and stability of the correction algorithm • Metrology for the convex, aspheric secondary • Achieving 5-sec slew-and-settle specification • Camera • Development of focal plane sensor meeting all specifications • Assembly of focal plane meeting flatness specification • Fabrication of the filters with spatially uniform passband • Data Management • Interfacing an individual investigator with the voluminous LSST data • Scientific algorithm development for credible prototyping of pipelines • Establishing catalog feature set and method for querying data base • System Engineering • Completing flow-down of scientific mission to perfomance specifications • Generating a complete end-to-end simulator • Establishing link between technical performance, cost, and schedule

  24. FPA Flatness Allocations Established Sensor Module 5mm p-v flatness over entire sensor surface Raft Assembly 6.5mm p-v flatness over entire surfaces of sensors Focal Plane Assembly 10mm p-v flatness over entire surfaces of sensors

  25. AlN UP Integrating structure Raft structure

  26. LSST highlights during the last year – Camera • Strawman camera designed with 3 GPixel camera • Flow-down of science requirements to performance requirements shows focal plane is achievable with CCD array • Favorable first results with Hybrid CMOS sensors • Preliminary camera optical and mechanical design completed • Vendor interaction confirms that refractive elements and filters can be manufactured

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