Cosmology with SNAP

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Cosmology with SNAP
Eric Linder Berkeley Lab
G. Aldering, C. Bebek, W. Carithers, S. Deustua,
W. Edwards, J. Frogel, D. Groom, S. Holland, D.
Huterer, D. Kasen, R. Knop, R. Lafever, M. Levi,
E. Linder, S. Loken, P. Nugent, S. Perlmutter, K.
Robinson (Lawrence Berkeley National
Laboratory) E. Commins, D. Curtis, G. Goldhaber,
J. R. Graham, S. Harris, P. Harvey, H. Heetderks,
A. Kim, M. Lampton, R. Lin, D. Pankow, C.
Pennypacker, A. Spadafora, G. F. Smoot (UC
Berkeley) C. Akerlof, D. Amidei, G. Bernstein, M.
Campbell, D. Levin, T. McKay, S. McKee, M.
Schubnell, G. Tarle , A. Tomasch (U. Michigan)
P. Astier, J.F. Genat, D. Hardin, J.- M. Levy,
R. Pain, K. Schamahneche (IN2P3) A. Baden, J.
Goodman, G. Sullivan (U.Maryland) R. Ellis, A.
Refregier (CalTech) A. Fruchter (STScI) L.
Bergstrom, A. Goobar (U. Stockholm) C. Lidman
(ESO) J. Rich (CEA/DAPNIA) A. Mourao (Inst.
Superior Tecnico,Lisbon)
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Probing Dark Energy Models
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Supernova Requirements
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From Science Goalsto Project Design
Science

• Measure ?M and ?
• Measure w and w (z)

Systematics Requirements
Statistical Requirements

• Identified and proposed systematics
• Measurements to eliminate / bound each one to
  /0.02 mag

• Sufficient (2000) numbers of SNe Ia
• distributed in redshift
• out to z lt 1.7

Data Set Requirements

• Discoveries 3.8 mag before max
• Spectroscopy with S/N10 at 15 Å bins
• Near-IR spectroscopy to 1.7 ?m

Satellite / Instrumentation Requirements

• 2-meter mirror Derived requirements
• 1-square degree imager High Earth orbit
• Spectrograph 50 Mb/sec bandwidth (0.35 ?m
  to 1.7 ?m)

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Mission Design

• SNAP a simple dedicated experiment to study the
  dark energy
• Dedicated instrument, essentially no moving parts
• Mirror 2 meter aperture sensitive to light from
  distant SN
• Photometry with 1x 1 billion pixel mosaic
  camera, high-resistivity, rad-tolerant p-type
  CCDs and, HgCdTe arrays. (0.35-1.7 mm)
• Integral field optical and IR spectroscopy
  0.35-1.7 mm, 2x2 FOV

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GigaCAM

• GigaCAM, a one billion pixel array
• Approximately 1 billion pixels
• 140 Large format CCD detectors required, 30
  HgCdTe Detectors
• Larger than SDSS camera, smaller than H.E.P.
  Vertex Detector (1 m2)
• Approx. 5 times size of FAME (MiDEX)

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Focal Plane Layout with Fixed Filters
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Step and Stare and Rotation
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High-Resistivity CCDs

• New kind of CCD developed at LBNL
• Better overall response than more costly
  thinned devices in use
• High-purity silicon has better radiation
  tolerance for space applications
• The CCDs can be abutted on all four sides
  enabling very large mosaic arrays
• Measured Quantum Efficiency at Lick Observatory
  (R. Stover)

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LBNL CCDs at NOAO
Science studies to date at NOAO using LBNL CCDs

1. Near-earth asteroids
2. Seyfert galaxy black holes
3. LBNL Supernova cosmology

Blue is H-alpha Green is SIII 9532Å Red is HeII
10124Å.
Cover picture taken at WIYN 3.5m with LBNL 2048
x 2048 CCD (Dumbbell Nebula, NGC 6853)
See September 2001 newsletter at
http//www.noao.edu
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Integral Field Unit Spectrograph Design
SNAP Design
Camera
Detector
Prism
Collimator
Slit Plane
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Lightcurves and Spectra from SNAP

• Goddard/Integrated Mission Design
• Center study in June 2001
• no mission tallpoles
• Goddard/Instrument Synthesis and
• Analysis Lab. study in Nov. 2001
• no technology tallpoles

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Science Reach

• Key Cosmological Studies
• Type II supernova
• Weak lensing
• Strong lensing
• Galaxy clustering
• Structure evolution
• Star formation/reionization

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A Resource for the Science Community

• SNAP main survey will be 4000x larger (and as
  deep)
• than the biggest HST deep survey, the ACS
  survey
• Complementary to NGST target selection for rare
  objects
• Can survey 1000 sq. deg. in a year to I29 or
  J28 (AB mag)
• Archive data distributed
• Guest Survey Program
• Whole sky can be observed every few months
• Galaxy populations and morphology to coadded
  m31
• Quasars to redshift 10
• Epoch of reionization through Gunn-Peterson
  effect
• Lensing projects
• Mass selected cluster catalogs
• Evolution of galaxy-mass correlation function