The SNAP Experiment

1
A French participation to SNAP
A.EALET
2
Outline

• Scientific interest
• Supernova in the world
• The French expertise in SN
• Historical participation
• The French participation to SNAP
• The spectrometer
• The scientific contribution

3
French scientific interest

• A long interest and large expertise in many area
  in cosmology
• Large scale structure
• Cluster of galaxies ..
• CMB
• SN ..
• Weak lensing
• A community motivated by fundamental questions
• inflation, dark matter and dark energy problems
  
• both theoretical and experimental sides (models
  , combination )
• A good synergy between theorists, physicists and
  cosmologists ..
• Two primary probes of SNAP well represented in
  the community..
• expertise in WL (Y.Mellier presentation)
• expertise in SN in collaboration with Berkeley
  since a long time

4
Supernovae around the world

• 1998- Past and current SCP , HZT, HST
• 2003-2008 Nearby SN factory
• 2003- SNLS, Essence w-project
• 2003- SDSS
• Future .
• LSST
• SNAP/JDEM

5
Some ground supernova surveys
Nearby SuperNova Factory 300 SN Ia (2003-2008),
zlt 0.1
SuperNovae CfA 100s SN Ia (1996-) petit z
The SN program of the CFHT Legacy Survey
(SNLS) 700 SN Ia (2003-2007) z lt 1
ESSENCE projet CTIO 200 SN Ia (2002-) z lt 0.75
6
SN Factory
Collaboration Franco-US Dedicated instrument,
SNIFS, for the spectro-photometric follow-up of
nearby (0.03ltzlt0.08) SN Ia built in France
(2000-2004) mounted on UH 2.2m (Hawaii) spring
2004
A key project for SN
SN Ia searches at Palomar and spectro-photometry
with SNIFS still improving. 60 well followed
SN 200 for end 2008
7
SNLS/ A french/canadien survey
40 nuits/an 5 ans 4 carré u,g,r,i,z g,r,i,z
toutes les les 2-3 nuits/ 10 mois Limite z
1.2 2000 SNIa SNII 700 SNIa bien mesurées
0.3ltzlt0.9

• 1 deg² Megacam camera
• Rolling search
• Queue observing, Multi-colour lightcurves
  (SNAP startegy)
• Spectroscopic follow up with large telescopes
• (VLT,Gemini,Keck)

8
SNLS-SDSS
Riess et al. 2004 w 1.02 0.13 0.19
Astier et al. 2005 WM 0.271 /- 0.021 (stat)
/- 0.007 (syst) w -1.023 /- 0.090 (stat) /-
0.054 (syst)
9
Supernovae in SNAP

• High level requirements from SN
• Going beyond z 1 gt IR
• A control of systematic uncertainties
• gt well measured light curves
• gt spectroscopy of each candidate at peak
• Precise photometry in 9 filters
• A spectrometer both in visible and IR

10
An historical collaboration

• Long time collaborators with Berkeley Physics
  Depart.
• (, Babar, and SCP in Paris
  (LPNHE/In2P3))
• 1990-gt1998 SCP
• pioneer work find distant SNe, measure
  LC, z
• gt Discovery of the acceleration of the
  expansion of the Universe
• Since collaboration in SN projects (SN Factory,
  SNLS )
• From SN to other sciences
• Implication of astrophysists in SNAP since 2000
• first through an instrumental optical expertise
• followed by an increase of the scientific
  implication ..
• Refregier and co in 2003 first WL studies
• JP Kneib, S. Arnouts, O.Ilbert .. WL, photo z
  ..
• A Mazure other science

11
The current French participation in SNAP

• 3 laboratories are official SNAP members 2
  IN2P3 (CPPM, LPNHE), 1 INSU (LAM)
• A strong organization in Marseille
• A integrated scientific and technical team (CPPM
  IN2P3/ LAM INSU)
• scientific expertises (Supernovae, lensing,
  photometric redshifts , galaxy evolution etc)
• A technical group project around the spectrometer
  
• A technical expertise around the telescope
• A participation for simulation at different
  levels (spectrometer software and photo z
  simulation)
• Collaboration with IPNL/CRAL at Lyon
• Close link with ASTRIUM
• Open to other contribution/participation

12
The french participation in SNAP

• a leadership on the spectrometer
• A slicer expertise in LAM
• A French responsibility
• A Strong integration inside the project
• (co-I for the AO concept studies )
• Complete development plan
• A demonstrator ( complete instrument) under
  construction to validate performances
• Development of the associated software
  (simulation and data acquisition)

13
Spectrometer road map
2002-2003
2004-2006
A first Slicer prototype
A new design
simulation
A first design
reconstruction
A demonstrator
14
A SNAP spectrometer demonstrator
H2RG
Spectro unit
Steering mirror
Detector
Offner relay
The slicer (5 slices)
The demonstrator is under alignment .. Work at
140 K with an H2RG Detector from SNAP using LAM
cryostat facilities
15
Next year telescope studies

• Telescope concept already well advanced
• Mainly from SN photometric requirements
• Need implementation of the WL shape
  requirements
• a possible french contribution
• Strong expertise of French vendors
• Astrium(SiC), Alcatel/Reosc (Light zerodur)
• CNES studies for 2007 with a scientific input
  of the SNAP French team members
• Interface with CNES and industrial(s)
• Interface with Berkeley scientific group WL and
  SN
• Scientific guidance on the French technical
  propositions
• Mission calibration
• AIT/AIV for the OTA (TBD)

16
Other possible contributions

• Experience in building large CCD arrays (MegaCam
  (1sq deg 40 2x4k CCD)
• Software Experience in image processing
• For SN SNfactory, CFHT LS 4 sq. deg.
  every 2nd night for 5 years
• For WL, Terapix (see Mellier talk)

17
Scientific contributions

• Science extension
• French groups are also working on weak (and
  strong) lensing
• 2002-2003 first studies (Massey, Refregier,
  Rhodes)
• since then, many actives groups in US
  (Bernstein, Jain et al., Rhodes et al. etc..)
• in France .. JP Kneib, O.Ilbert, S.Arnouts
• Current studies going on
• Method ptimization (cross correlation,
  tomography ..)
• Optimization of the survey size, depth
• Estimation of systematic errors uncertainties
• photometric redshift determination and precision
  
• Filter optimization and photo z calibration with
  IR spectroscopic calibration

18
Science extension

• Science extension
• A spatial wide field imager both visible and IR
  with 9 filters
• .A dream for astronomers
• .a billion z machine
• Galaxy evolution
• Quasars et AGN
• Solar system
• Large structure,
• High z objects ..
• First galaxies and quasars
• Future possible synergy with future large
  projects as JWST/ELT
• ( target selection for multi object spectrograph
  in 10 degr2 at m 30 in 9 bands in 2016)