1 A French participation to SNAP A.EALET

2Outline 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 — 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 ( ), z< 0.1 The SN program of the CFHT Legacy Survey (SNLS) 700 SN Ia ( ) z < 1 SuperNovae CfA 100’s SN Ia (1996-) petit z ESSENCE projet CTIO 200 SN Ia (2002-) z < 0.75 French instruments SNIFS : IFU spectrometer MEGACAM : Wide field imager. With a collaboration With Berkeley

6 SN Factory Collaboration Franco-US Dedicated instrument, SNIFS, for the spectro- photometric follow-up of nearby (0.03<z<0.08) SN Ia : built in France ( ) mounted on UH 2.2m (Hawaii) spring 2004 SN Ia searches at Palomar and spectro-photometry with SNIFS still improving. ~60 well followed SN ~200 for end 2008 A key project for SN

7 SNLS/ A french/canadien survey 1 deg² Megacam camera Rolling search Queue observing, Multi-colour lightcurves (SNAP startegy) Spectroscopic follow up with large telescopes (VLT,Gemini,Keck) 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 = SNIa + SNII +… 700 SNIa bien mesurées 0.3<z<0.9

8 SNLS-SDSS Astier et al. 2005:  M = / (stat) +/ (syst) w = / (stat) +/ (syst) Riess et al w = – – 0.19

9 Supernovae in SNAP High level requirements from SN Going beyond z= 1 => IR A control of systematic uncertainties => well measured light curves => 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->1998 SCP: pioneer work : find distant SNe, measure LC, z => 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 A first Slicer prototype A first design simulation reconstruction A new design A demonstrator

14 A SNAP spectrometer demonstrator The demonstrator is under alignment.. Work at 140 K with an H2RG Detector from SNAP using LAM cryostat facilities Steering mirror Spectro unit H2RG Detector Offner relay The slicer (5 slices)

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)  ….A finaliser demain…..

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 2 nd 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 : 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 —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)