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

2 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 –Two 15 second Exposures Data Storage and Pipelines Included in Project

3 Why is the LSST unique? Primary mirror diameter Field of view (full moon is 0.5 degrees) Keck Telescope 0.2 degrees 10 m 3.5 degrees LSST

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 Optical Design 0.6” LSST Optical Design

13 LSST Camera

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

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

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

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

23 Key R&D Issues Telescope 1.Implementation of the wavefront sensor and stability of the correction algorithm 2.Metrology for the convex, aspheric secondary 3.Achieving 5-sec slew-and-settle specification Camera 1.Development of focal plane sensor meeting all specifications 2.Assembly of focal plane meeting flatness specification 3.Fabrication of the filters with spatially uniform passband Data Management 1.Interfacing an individual investigator with the voluminous LSST data 2.Scientific algorithm development for credible prototyping of pipelines 3.Establishing catalog feature set and method for querying data base System Engineering 1.Completing flow-down of scientific mission to perfomance specifications 2.Generating a complete end-to-end simulator 3.Establishing link between technical performance, cost, and schedule

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

25 Integrating structure Raft structure AlN UP

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