XXIIIrd IAP Colloquium, July 2nd 2007, Paris Cosmic shear using Canada-France-Hawaii Telescope Legacy Survey (Wide) Liping Fu Institut d’Astrophysique de Paris "From giant arcs to CMB lensing: 20 years of gravitational distortion" XXIIIrd IAP Colloquium July 2 nd, 2007

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Canada: H. Hoekstra (U. Victoria) L. van Waerbeke (UBC, Vancouver) C. Heymans (UBC/IAP) J. Benjamin (UBC) S. Gwyn (U. Victoria) M. Hudson (U. Waterloo) L. Parker (U. Waterloo/ESO) B. Menard (CITA) U.L. Pen (CITA) O. Dore(CITA) Collaboration France: L. Fu (IAP) E. Semboloni (Bonn/IAP) I. Tereno (Bonn/IAP) Y. Mellier (IAP) M. Kilbinger (IAP) J. Coupon (IAP) E. Bertin (IAP) H.J. McCracken (IAP) O. Ilbert (UBDA) K. Benabed (IAP) R. Maoli (U.Rome/IAP) F. Bernardeau (CEA/SPhT) M. Dantel-Fort (LERMA) F. Magnard (IAP) C. Marmo (IAP) M. Schultheis (Obs. Besançon) J.P. Uzan (IAP) C. Schimd (CEA/SPP and IAP)

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Outline  Introduction to CFTHLS  Pipeline reliability  Cosmic shear on large scales  Cosmological parameter constraints

XXIIIrd IAP Colloquium, July 2nd 2007, Paris I. Canada-France-Hawaii Telescope Legacy Survey

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Terapix/Skywatcher : all data 03A-05A : Megacam images W2 D4 W3 & D3 D2 Canada-France-Hawaii Telescope Legacy Survey: Canada-France collaboration nights between June 2003 and June CFHTLS-Wide ( 170 deg2 ), 4 CFHTLS-Deep ( 1 deg2 each ) HST Groth strip GEMINI-N visibility VLT visibility VLT visibility + XMM fields VVDS spectro. survey VLT visibility + HST-Cosmos VLT visibility + Quasar field W1 & D1  3.6 m ground telescope  MegaCam: 36 CCDs, 1 o × 1 o  Pixel size: 0.186”  u g r i z bands W4 VVDS UKIDSS DXS

XXIIIrd IAP Colloquium, July 2nd 2007, Paris W1 (19 deg 2 )W2 (8 deg 2 )W3 (30 deg 2 ) Sky coverage of CFHTLS Wide (the 3rd release): 57 deg 2 Number of Pairs CFHTLS Wide:  57 deg 2 (35% completed)  W2 is new compared with 1 st release  mag lim = 24.5 i-band  A eff = 35 deg 2 (conservative masking); n eff = 12 gal/arcm 2  2.5 ×10 6 galaxies

XXIIIrd IAP Colloquium, July 2nd 2007, Paris II. Pipeline reliability

XXIIIrd IAP Colloquium, July 2nd 2007, Paris the multiplicative “calibration bias” the additive “residual shear offset” Unbiased shear measurement on Shear TEsting Program (STEP; see Kuijken’s talk) STEP1STEP2 “0,…5” & “A,…F”: Realistic PSF models in simulations

XXIIIrd IAP Colloquium, July 2nd 2007, Paris III. Cosmic shear on large scales using CFHTLS Wide (the 3 rd release) Two publication (the 1 st release): Semboloni et al., 2006 (Deep) Semboloni et al., 2006 (Deep) Hoekstra et al., 2006 (Wide) Hoekstra et al., 2006 (Wide)

Cosmic shear signal on large scales Sky coverage: 57 deg2 up to 460’ up to: 230’ No B-mode Error bars (Schneider et al. 2002) : Non-Gaussianity calibrated (Semboloni et al. 2006)

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Large scales zoom in (26’~230’)  Reliable Shear analysis till 4 degrees  Large scales signal will reduce the effect of small scales systematics (non- linear evolution of power spectrum; intrinsic alignment)

XXIIIrd IAP Colloquium, July 2nd 2007, Paris The consistency of W1, W2 and W3  Scales up to: W1 200’ (19 deg 2 ) W1 200’ (19 deg 2 ) W2 120’ (8 deg 2 ) W2 120’ (8 deg 2 ) W3 230’ (30 deg 2 ) W3 230’ (30 deg 2 )  2pt correlation functions Consistency !

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Shear cross checking and systematics  Consistent shear signal C ommon objects using two independent pipelines: French: LF = L. Fu Canadian: HH = H. Hoekstra  No systematics French Canadian

XXIIIrd IAP Colloquium, July 2nd 2007, Paris IV. Cosmological parameter constraints

XXIIIrd IAP Colloquium, July 2nd 2007, Paris  Redshift distribution a single lens-plane + CFHTLS Deep Photo-z (500,000 galaxies, Ilbert et al. 2006) z Less complete WL selection criteria WL weighting scheme  Shear and cosmological parameters 21.5 < mag _ i < 24.5 = Error bars: photo-z uncertainty + poisson error + sample variance (van Waerbeke et al, 2006) z Bootstrap

XXIIIrd IAP Colloquium, July 2nd 2007, Paris flat model likelihood of CS:, grid (other parameters are fixed) likelihood of ; taken as a prior Non-linear scheme: halo-fit  Non-linear scheme: P&D (1996) and halo-fit (Smith et al., 2003) Marginalization:

XXIIIrd IAP Colloquium, July 2nd 2007, Paris  Comparison of constraints from different scales 1’~230’26’~230’ Full scales constraints: 2% difference No small scales constraints: less than 1% difference Systematics? Compare P&D and halo-fit model:

XXIIIrd IAP Colloquium, July 2nd 2007, Paris  Comparison with Benjamin et al., 2007 Comparison with previous constraints 100 deg 2 CFHTLS Wide + RCS + VIRMOS-DESCART + GaBoDS CFHTLS-wide (1 st ) A eff = 22 deg 2 CFHTLS-wide (3 rd ) A eff = 35 deg 2

XXIIIrd IAP Colloquium, July 2nd 2007, Paris  Comparison with WMAP3 (Spergel et al., 2006) WMAP3 CFHTLS Wide (3 rd )

XXIIIrd IAP Colloquium, July 2nd 2007, Paris  Non-linear power spectrum (Peacock & Dodds, 1996)  Marginalizing over  Flat model (68% c.l.) The constant equation of state: Probing dark energy

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Conclusion  Unbiased shear measurement calibrated on simulations and cross- checked with independent pipeline  Reliable Shear analysis up to large scales : 4 degrees  The use of large scales reduce the effect of small scales systematics (non-linear evolution of power spectrum; intrinsic alignment)  The cosmological parameter constraints (68% c.l.)  Constraints consistent with WMAP3  The redshift degeneracy will be further minimized with the photometric redshifts measured from the new release (T4, Work in progress)

XXIIIrd IAP Colloquium, July 2nd 2007, Paris

Covariance matrix  Gaussian covariance matrix taking masking and survey geometry into account (Schneider et al. 2002)  Non-Gaussian calibration (Semboloni et al. 2006)

XXIIIrd IAP Colloquium, July 2nd 2007, Paris  Weighting scheme of weak lensing

XXIIIrd IAP Colloquium, July 2nd 2007, Paris =  s +  i + noise + systematics …. Weak lensing and Galaxy shape: Weak lensing regime :  ~ 2  = ‹  S hear ›  + noise Assume sources orientation is isotropic : Mellier 1999 δ ~ 2γ (weak lensing regime) PSF anisotropy correction Derived from star shape analysis. Reliability of results: depends on PSF analysis

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Cosmic shear probes the dark matter power spectrum  Two-point statistics  Convergence (projected mass) power spectrum ( Blandford et al 1991, Miralda-Escud é 1991, Kaiser 1992,1998, Bernardeau et al 1997, Jain & Seljak 1997, Schneider et al 1998 ) Redshift distribution 2D power spectrum

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Expansion and growth rate of structures as function of DM and DE content of the universe Supernovae Weak lensing a Goal of CFHTLS Cosmic Shear Survey: observe P(k) and P(k,z) using weak lensing and compare its properties with cosmological models.

XXIIIrd IAP Colloquium, July 2nd 2007, Paris Weak gravitational lensing and cosmology: Light propagation in inhomogeneous universes Bartelmann & Schneider 2001; Erben 2002 ds 2 =c 2 dt 2 - a 2 (t) [dw 2 + f K 2 (w) d  2 ] Deflection angle: Distances (Geometry) Power spectrum, growth rate of structure Depend on dark matter and dark energy