The SNAP Project at SLAC Phil Marshall SLAC/KIPAC Slide 1

KIPAC is playing an active role in the SNAP project, a strong contender for the JDEM mission Overview of the SNAP telescope: motivation, primary science experiments, system design Hardware development at SLAC (Kahn, Althouse, Craig, Huffer) Strong lens survey science (Blandford, Marshall, with Baltz, Bradac and Sako) Pre-cursor datasets: the HAGGLeS project Summary Slide 2 Outline

Multiple complementary experiments, allowing marginalisation over dark matter and baryonic astrophysics Measuring the distance scale with type Ia supernovae Slide 3 Probing Dark Energy (Riess et al 2004, Aldering, KIPAC et al 2005)

Multiple complementary experiments, allowing marginalisation over dark matter and baryonic astrophysics The distance scale with type Ia supernovae The low-redshift matter power spectrum, growth of structure and cosmic geometry with weak gravitational lensing Slide 4 Probing Dark Energy 1 arcmin

Multiple complementary experiments, allowing marginalisation over dark matter and baryonic astrophysics The distance scale with type Ia supernovae The low-redshift matter power spectrum, growth of structure and cosmic geometry with weak gravitational lensing Systematics-limited measurements Complementarity/vital cross-checking Copious ancillary science for free... Slide 5 Probing Dark Energy

2-metre class telescope Optical and NIR imager, 0.7 square degree f.o.v. 0.13” PSF, 0.1” pixels, cf. WFPC2 9 matched, fixed filters Multi-object (IFU) spectrograph L2 orbit, dedicated telemetry base station Slide 6 The SNAP design

Lead institution for development of Instrument Control Unit (ICU) Slide 7 SLAC: hardware

Lead institution for development of Instrument Control Unit (ICU) Network-centric approach allows greater flexibility, solves mass- memory problem, improved efficiency and throughput Slide 8 SLAC: hardware Redundant NMI FPA SBC NMI instrument SBC Primary ICU DLI Instrument Router A Instrument Router B Primary DVI 1 DVI 34 DVI 0 DVI 35 NMI FPA FPA Router A FPA Router B NMI instrument

Lead institution for development of Instrument Control Unit (ICU) Also designing fine guider system: ✔ Crucial component enables milliarcsecond pointing corrections ✔ Guiders will be prototyped at SLAC over next year Slide 9 SLAC: hardware CHU#1 CHU#2 CHU#3 CHU#4

Lead institution for development of Instrument Control Unit (ICU) Flexible network-centric approach proposed Distributed memory part of scheme adopted at this stage R&D phase continues Fine guiding solution is the baseline for SNAP Prototyping over the next year as part of SNAP project technology demonstration Slide 10 SLAC: hardware

KIPAC is leading the Strong Gravitational Lensing Working Group: SNAP imaging data well matched to an idealised strong lens survey 9 filters (6 optical + 3 NIR) for SN typing and WL galaxy photo-z 0.1” angular resolution, stable PSF cf. WFPC2 on HST – but 650 times larger field of view (0.7 sq. deg.) Slide 11 SLAC: Science (Aldering et al 2005)

Elliptical galaxy lens galaxies with achromatic residuals HST resolution: galaxy sources Slide 12 Slide title – Garamond 40

In 1000 sq. deg, expect: ~20 million ellipticals ~20000 eg-g lenses ~500 eg-q lenses (cf. ~100 currently known lens systems) Slide 13 Strong lens surveying Initial cut (1000 to few) all important in “expert” system Lens modeling of c systems “Low resolution spectra” for redshifts and lens mass

Dark matter in elliptical galaxies: density profile (e.g. Rusin et al 2003), relation to luminous matter (e.g. Treu & Koopmans), Small-scale CDM substructure, from flux ratios (e.g. Bradac et al 2004), and image curvature (Irwin & Shmakova 2005): Slide 14 Science case Redshifts of faintest galaxies / cosmography from distance ratios...

Slide 15 Distance ratios Image separation is proportional to distance ratio: Extracting cosmology requires accurate knowledge of fundamental plane (and its evolution), and of the source redshifts...

All ~20000 SNAP lenses may be monitored by LSST Supernovae in lensed galaxies make excellent features in the light curves for measuring time delays: expect c in ten-year LSST survey, with c. 10 day time resolution Sensitivity to lens model is reduced for this subset: Slide 16 Synergy with LSST Figures from Goobar et al 2002

HST archive is the precursor dataset Deep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 10 4 elliptical galaxies, c. 25 lenses... Numbers on borderline between eyeball and automated search Slide 17 Life before SNAP: HAGGLeS

HST archive is the precursor dataset Deep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 10 4 elliptical galaxies, c. 25 lenses... Numbers on borderline between eyeball and automated search Funded as HST Archive Legacy project in April 2005 Slide 18 Life before SNAP: HAGGLeS

HST archive is the precursor dataset Deep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 10 4 elliptical galaxies, c. 25 lenses... Numbers on borderline between eyeball and automated search Funded as HST Archive Legacy project in April 2005 Pilot projects (SDSS LRGs, and UDF) underway Slide 19 Life before SNAP: HAGGLeS

HST archive is the precursor dataset Deep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 10 4 elliptical galaxies, c. 25 lenses... Numbers on borderline between eyeball and automated search Funded as HST Archive Legacy project in April 2005 Pilot projects (SDSS LRGs, and UDF) underway Slide 20 Life before SNAP: HAGGLeS

HST archive is the precursor dataset Deep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 10 4 elliptical galaxies, c. 25 lenses... Numbers on borderline between eyeball and automated search Funded as HST Archive Legacy project in April 2005 Pilot projects (SDSS LRGs, and UDF) underway Slide 21 Life before SNAP: HAGGLeS

KIPAC is actively and enthusiastically involved in both hardware and software development for SNAP The wide survey will increase the galaxy-scale strong lens sample size by 2 orders of magnitude over the current number Statistical studies of dark matter in elliptical galaxies, the faintest source galaxies, and potentially dark energy will be possible This survey will be highly complementary to its LSST counterpart An expert system for automated lens identification is under development as part of the HAGGLeS project: new lenses will be discovered en route Slide 22 Summary