2. LSST Camera Project SLAC EPAC Meeting Nov. 14-15, 2003 1 The Large Synoptic Survey Telescope (LSST) Presentation to the Experimental Program Advisory Committee at SLAC November 14, 2003

3. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20032 The Large Synoptic Survey Telescope The LSST will be a large, wide-field ground-based telescope designed to survey the entire visible sky every few nights. This project concept has been strongly endorsed by three separate National Academy committee reports: Astronomy and Astrophysics in the New Millennium, New Frontiers in the Solar System, and Connecting Quarks with the Cosmos. LSST will enable a wide variety of complementary scientific investigations, utilizing a common database. These range from searches for small bodies in the solar system to precision astrometry of the outer regions of the galaxy to systematic monitoring for transient phenomena in the optical sky. Of particular interest to HEP, LSST will constrain models of dark energy vs. cosmic time by measuring the dark matter power spectral density via weak lensing.

4. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20033 SLAC Involvement in LSST The Kavli Institute for Particle Astrophysics and Cosmology (KIPAC) has chosen to emphasize dark matter and dark energy as key focus areas for its experimental program at SLAC. We believe it is essential to probe the standard cosmological model on multiple “fronts”, i.e. not only constraining parameters, but testing for internal consistency via disparate measurement techniques. LSST is an excellent complement to SNAP. By participating in BOTH projects, we believe that SLAC will be ideally positioned to play a key role in the next wave of cosmological discovery.

5. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20034 Outline of Presentations Probing Dark Energy with LSST – A. Tyson The Design and Development of the LSST Camera – W. Althouse LSST Project Organization – S. Kahn

6. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20035 Physical Observables: probing DE 1. Luminosity distance vs. redshift: d L (z) “ Standard” candles: SNe Ia 2. Number counts vs. redshift: N(M,z) *Comoving Volume element dV/dzd  *Growth rate of density perturbations  (z) Counts of mass clusters: 3-D tomography 3. Shear Tomography: 4. Sachs-Wolfe effect:

7. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20036 LSST probes of DE Number counts vs. redshift 1. Number counts vs. redshift: N(M,z) *Comoving Volume element dV/dzd  *Growth rate of density perturbations  (z) Counts of mass clusters: 3-D tomography Shear Tomography 2. Shear Tomography: 3. Sachs-Wolfe effect:

8. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20037 mass structure vs time 7 billion lyr 3 billion lyr

9. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20038 Weak Gravitational Lensing Over 250,000 resolved hi-redshift galaxies per square degree Each is moved on the sky and distorted

10. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 20039 Strong lensing

11. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200310

12. The blue galaxy is sheared more than the red galaxy. The green galaxy is not sheared. Cluster Tomography Mass Cluster @ z = 0.5 Foreground Source D lens D source Lens Strength z z source P(z) Source Redshift Distribution Distant Source Galaxies z lens = 0.5 1 - D lens /D source z z source Lens Strength

13. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200312 Tomographic mass slices in z

14. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200313 Observed mass: 2x2 degree field z =.7

15. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200314 DLS 1055-05

16. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200315 mass – baryon correlation? DLS mass map CXO.5-4 keV

17. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200316 Mass Cluster Counting The mass function is steep and exponentially sensitive to errors in M limit (z) and uncertainty in M(observables,z). Measure mass function, determine M limit (z) from LSST cluster survey, devise a test that is insensitive to the limiting mass.

18. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200317 Goal: Determine cosmological parameters by comparing the observed distribution of clusters to predictions from theory/N-body simulations However cluster mass is not an observable. Instead we measure:  SZ decrement  X-rays (L X or T X )  Optical Richness  Galaxy  v  Shear  To interpret the observations we must know  M ( observables,z )  Completeness( observables,z ) Cluster Counting No baryon bias

19. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200318 QCDM or LCDM? Redshift distributions differ at a high statistical significance Lensing kernel is broader for LCDM and probes a broader range of z and M than QCDM w precision 2% Unlike other cluster counting surveys, this test is ROBUST against uncertainties in mass limit. LCDM QCDM Normalized Cluster Redshift Distribution

20. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200319 Cosmic shear vs redshift

21. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200320 LSST shear tomography +

22. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200321 Precision on DE P/  P/  = w 0 + w a (1- a) a = (1+ z) -1  CDM SUGRA SNAP SN + Planck LSST WL + WMAP SNAP WL + Planck

23. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200322 LSST Weak Lensing survey Low z WL

24. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200323 Weak Lensing with LSST Summary An incisive probe of new physics: 3-D tomography / Dark Energy Multiple probes break degeneracies Probes dark energy in multiple ways: w and dw/dz from shear-shear and cluster dN/dz.  m,  x curves. Comparison with CMB and with SN1a tests fundamental assumptions

25. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200324 Controlling Systematics Need baryon unbiased estimates of cluster mass shear survey Minimize delivered PSF shear Chop shear signal multiple ways Large sample of mass clusters Explore mass function

26. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200325 Figure of Merit Volume surveyed (number of objects found) to some S/N at some magnitude limit, per unit time: A – aperture  – camera FOV QE – det. Eff.  – observing eff.  sky – sky flux  – seeing footprint site & optics Apparatus & Eff. Science goals

27. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200326 Optical Throughput Required LSST

28. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200327 Unexplained optical bursts Deep Lens Survey

29. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200328 Massively Parallel Astrophysics LSST DATA PUBLIC Simultaneously address: – Dark matter/dark energy via weak lensing – Dark matter/dark energy via supernovae – Galactic Structure encompassing local group – Dense astrometry over 30000 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. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200329

31. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200330 LSST Optics

32. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200331 Camera Configuration

33. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200332

34. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200333 Camera Components Focal plane array –10 μm pixels  0.2 arcsecond/pixel (~ 1 / 3 seeing-limited PSF) –55 cm diameter  3° FOV  2.3 Gpixels –integrated front-end electronics –16 bits/pixel, 2 sec readout time  2.3 GB/sec  Parallel readout Housings (environmental control) Filters Optics Mechanisms –L2 position varies with wavelength (filter) –Filters insertion –mechanical shutter

35. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200334 Camera Challenges Detector requirements: –10 μm pixel size –Pixel full-well > 90,000 e – –Low noise (< 5 e – rms), fast (< 2 sec) readout (  < –30 C) –High QE 400 – 1000 nm –All of above exist, but not simultaneously in one detector Focal plane position precision of order 3 μm Package large number of detectors, with integrated readout electronics, with high fill factor and serviceable design Large diameter filter coatings Constrained volume (camera in beam) –Makes shutter, filter exchange mechanisms challenging Constrained power dissipation to ambient –To limit thermal gradients in optical beam –Requires conductive cooling with low vibration

36. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200335 Camera Challenges (con’d) Key challenge: Detector technology Main choices: CCD, hybrid CMOS –CCDs: Monolithic Si array Routinely used for visible astronomical applications Have been made in high-resistivity, thick format (to achieve sensitivity at 1 μm wavelength) with 15 μm pixel density Slow readout: need ~10 μs per pixel to achieve noise level –Hybrid CMOS: Hybrid array uses thin planar detector with pixelated back contact “bump bonded” to CMOS readout multiplexer Routinely used for infrared astronomy (with different photo- conversion material) Avoids need for mechanical shutter Can integrate substantial electronics on-chip Low power (< 1/100 of CCD) & Fast readout

37. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200336 Camera Challenges (con’d) Control of systematics –Lensing studies exploit subtle, systematic image distortions caused by dark matter –Time dependent or environmentally induced distortion in the measuring system (telescope + camera) could mask the lensing signature –May place unusual demands on camera development, particularly testing to ensure acceptable control/knowledge of end-to-end transfer function

38. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200337 LSST Management Plan In March 2003, four organizations (U. of Washington, U. of Arizona, the Research Corporation, and NOAO) formed the LSST Corporation (LSSTC), a non-profit 501C3 Arizona corporation. The purpose of LSSTC is to pursue a shared vision for the nature of the LSST endeavor, and a commitment to advance the project through technical, scientific, and/or financial contributions. LSSTC plans to expand its institutional membership as the project progresses. As presently envisioned, funding for the construction of the LSST will come from NSF, DOE, and private donors. Significant commitments of private funding are already in hand. A proposal to NSF for design & development phase funding will be submitted in December 2003. While LSST is a distributed project, there is a single management plan. All participating organizations will be coordinated and accountable to the LSST Director and Project Manager, who are appointed by the LSSTC Board of Directors.

39. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200338 DOE Participation in LSST A collaboration of DOE-funded institutions has been formed to pursue participation in LSST. This collaboration has been working closely with other LSST participants under the coordination of the LSST Director and Project Manager. The DOE “deliverable” will be the LSST camera system. SLAC will lead the development of the camera, with significant contributions coming from BNL, LLNL, and DOE-funded university groups (e.g. Harvard, UIUC). Scientists and engineers at these institutions will also participate in the data acquisition system, the development of pipeline software, and the scientific interpretation of the results.

40. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200339 Camera Steve Kahn, Sci. Bill Althouse, Mgr. Telescope/Site Charles Claver, Sci. Larry Daggert, Mgr. System Engineering Jacques Sebag Project Support Change Control Board Risk Management Project Controls Performance Assurance Administration Science Working Groups Data Management Kem Cook, Sci. tbd, Mgr. LSST Director Anthony Tyson Science Advisory Board Zeljko Ivezic, Philip Pinto Project Manager Donald Sweeney Science Assurance System Scientist Christopher Stubbs Data: Kem Cook Camera: Steve Kahn Tel/Site: Chuck Claver Array Technology Don Figer, Mike Lesser SW Architecture Jim Gray, Robert Lupton Public Outreach Michael Shara, Doug Isbell External Review Board LSST Project Organization LSST Corporation Board of Directors John Schaefer, President Research Corporation, University of Washington, National Optical Astronomical Observatory, University of Arizona Executive Advisory Committee Arthur Bienenstock

41. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200340 LSST Camera Project Organization Lead Mech. Engr T. Decker, LLNL Lead Elect. Engr J. Oliver, Harvard Focal Plane Assy M. May, BNL Optics J. Taylor, LLNL S. Olivier, LLNL Mechanisms L. Hale, LLNL Housing & Structure T. Thurston Camera I&T W. Craig Data Bus W. Althouse (act.) Camera Project Support Project Controls & Risk Mgmt Performance & Safety Assur. Administration Camera S. Kahn, Sci Lead W. Althouse, Proj Mgr System Engineering T. Thurston All SLAC unless otherwise noted Array Testing D. Figer, STScI M. Lesser, Steward Obs. Array, FE Elex V. Radeka, BNL Opto-Mech Assy T. Decker, LLNL

42. LSST Camera ProjectSLAC EPAC Meeting Nov. 14-15, 200341 LSST Design Phase Schedule