The SNAP Project at SLAC

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 astrophysicsMeasuring 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 astrophysicsThe distance scale with type Ia supernovaeThe 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 astrophysicsThe distance scale with type Ia supernovaeThe low-redshift matter power spectrum, growth of structure and cosmic geometry with weak gravitational lensing

Systematics-limited measurementsComplementarity/vital cross-checking

Copious ancillary science for free...

Slide 5

Probing Dark Energy

2-metre class telescopeOptical and NIR imager, 0.7 square degree f.o.v.0.13” PSF, 0.1” pixels, cf. WFPC29 matched, fixed filtersMulti-object (IFU) spectrographL2 orbit, dedicated telemetry base station

Slide 6

The SNAP design

Lead institution for development of Instrument Control Unit (ICU)

Slide 7

SNAP @ 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


Redundant

NMIFPA

SBC

NMIinstrument

SBC

Primary ICU

DLI DLI

Instrument RouterA

Instrument RouterB

Primary

DVI1 DVI34DVI0 DVI35

NMIFPA

FPA RouterA

FPA RouterB

NMIinstrument


Also designing fine guider

system: ✔ Crucial component enables milliarcsecond pointing corrections

✔ Guiders will be prototyped at SLAC over next year

Slide 9


CHU#1

CHU#2

CHU#3

CHU#4


Flexible network-centric approach proposedDistributed memory part of scheme adopted at this stageR&D phase continues

Fine guiding solution is the baseline for SNAPPrototyping over the next year as part of SNAP project technology demonstration

Slide 10


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 PSFcf. WFPC2 on HST – but 650 times larger field of view (0.7 sq. deg.)

Slide 11

SNAP @ SLAC: Science

survey driver area / sq. degdepth / AB mag

Wide WL 1000 26.6

Deep SN 15 28.9 (Aldering et al 2005)

Elliptical galaxy lens galaxies with achromatic residualsHST 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” systemLens modeling of c. 105 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...

0 1000 2000 3000 4000

0

1000

2000

3000

4000

1.12 2.21.64

0.961.92 1.28 1.21.6

1.64 1.321.481.64

2.082.44 1.721.72

1.081.92

2.08 1.922.16

1.28 1.161.04 2.24

1.642.081.08 1.52

1.440.88 1.64 1.61.48

3.2

1.441.242.163.2.322.72

1.161.56 2.20.961.24

1.72

1.64

1.6

2.32 1.12 1.81.64 4.321.28

1.283.62.161.72

1.12 2.21.64

0.961.92 1.28 1.21.6

1.64 1.321.481.64

2.082.44 1.721.72

1.081.92

1.92

2.08 1.920.922.16

1.28 1.161.04 1.2.24

1.642.081.08 1.52

1.440.88 1.64 1.61.48 1.921.16

1.23.2

3.1.441.242.163.2.322.72

2.921.161.56 2.20.96

1.241.72

1.64 2.281.

1.6

1.81.72

1.6

0.72

0.28

0.760.6 0.640.40.44 0.44

0.2

0.680.68

0.04 0. 0.160.28

0.040.560.720.68

0.48

0.52 0.60.2

0.6 0.72

0.36

0.0.28

0.080.04

0.72

0.20.08

Distance ratios

Image separation is proportional to distance ratio:

Extracting cosmology requiresaccurate knowledge of fundamental plane (and itsevolution), and of the sourceredshifts...

All ~20000 SNAP lenses may be monitored by LSSTSupernovae in lensed galaxies make excellent features in the light curves for measuring time delays: expect c. 1600 in ten-year LSST survey, with c. 10 day time resolutionSensitivity to lens model is reduced for this subset:

Slide 16

Synergy with LSST

Figures from Goobar et al 2002

HST archive is the precursor datasetDeep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 104 elliptical galaxies, c. 25 lenses...Numbers on borderline between eyeball and automated search

Slide 17

Life before SNAP: HAGGLeS

HST archive is the precursor datasetDeep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 104 elliptical galaxies, c. 25 lenses...Numbers on borderline between eyeball and automated searchFunded as HST Archive Legacy project in April 2005

Slide 18


HST archive is the precursor datasetDeep, multi-filter, high galactic latitude coverage is 2.2 sq degrees 104 elliptical galaxies, c. 25 lenses...Numbers on borderline between eyeball and automated searchFunded as HST Archive Legacy project in April 2005Pilot projects (SDSS LRGs, and UDF) underway

Slide 19



Slide 20



Slide 21


KIPAC is actively and enthusiastically involved in both hardware and software development for SNAPThe 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 possibleThis survey will be highly complementary to its LSST counterpartAn 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

The SNAP Project at SLAC

Documents

Transcript of The SNAP Project at SLAC