Catherine Heymans. Observing the Dark Universe with the Canada- France Hawaii Telescope Lensing Survey

Transcription

1 Observing the Dark Universe with the Canada- France Hawaii Telescope Lensing Survey Catherine Heymans Institute for Astronomy, University of Edinburgh

2 The intervening dark matter lenses the light from distant galaxies. Weak Gravitational Lensing

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4 Before lensing galaxies are randomly oriented*

5 Weak Gravitational Lensing Dark Matter Galaxies Lensed galaxies align

6 Clowe/Bradac et al

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8 LSST forecast Ivezic et al 2011

9 CFHTLenS Survey Statistics 155 sq degrees, ugriz to i<24.7 (CFHTLS) High resolution: 17 gals per sq arcmin Deep imaging: zm = 0.75 Accurate redshifts: σz= 0.04(1+z) with 4% outliers Accurate shear: <m> = <c> = Robust to systematic errors: 75% of the data used

10 The CFHT Lensing Survey UBC L. Van Waerbeke (PI) J. Benjamin H.Hildebrandt M. Milkeraitis S.Vafaei Edinburgh C. Heymans (PI) T. Kitching E. Grocutt A. Heavens F. Simpson Bonn T. Erben P. Simon T. Schrabback K. Holhjem Leiden H. Hoekstra K. Kuijken E. Semboloni E. van Uitert M. Smit Oxford L. Miller M. Velander IAP Y. Mellier R. Gavazzi Munich M. Kilbinger Waterloo M Hudson B. Gillis CSIC/IEEC C. Bonnett Shanghai L. Fu Tohoku J. Coupon UCL/JPL B. Rowe

11 Dark Matter changes the shapes of galaxies by ~1% Telescopes and the Atmosphere change the shapes of galaxies by ~15% Kitching et al 2010 We need to understand our instrumentation, modelling and analysis techniques to very high precision

12 Multi-epoch vs stacked data Slide from Henk Hoekstra

13 Kilbinger et al 2013

14 How aligned the galaxy pairs are Galaxy pair separation Kilbinger et al 2013

15 Fu et al 2008: Stack analysis Kilbinger et al 2013: Multi-epoch analysis Signal Signal Systematics Systematics θ (arcmin) θ (arcmin)

16 Galaxy-Galaxy Cosmology insensitive test of redshift-scaling [0.2,0.4] [0.4,0.5] [0.5,0.7] [0.7,0.9] [0.9,1.3] <! t > at "=1 arcmin Heymans et al mean photometric redshift sources

17 Cosmic Shear Cosmology sensitive measure of redshift-scaling How aligned the galaxy pairs are Heymans et al 2013

18 Flat LCDM Heymans et al 2013 ij + ( )= dk k J 0 (k ) Survey depth dw G i (w) G j (w) P Non-linear PS (Ωm ΩΔ σ8 w Η0..) k f k (w),w

19 Beyond-Einstein gravity theories ds 2 = (1 + 2 )dt 2 + a 2 (t)(1 + 2 )dx 2 Dynamical Potential Space Curvature Potential Poissons Equation 2 =4 Ga 2 GR fully tested on solar system scales, so any modification must be length or time dependent

20 Beyond-Einstein gravity theories ds 2 = (1 + 2 )dt 2 + a 2 (t)(1 + 2 )dx 2 Dynamical Potential Space Curvature Potential 2 ] =4 Ga 2 [1 + µ(a)] 2 [ + ] =8 Ga 2 [1 + (a)]

21 10 4 GR µ 0 = 0.5 Σ 0 = 0.5 CFHTLenS: relativistic ξ ± ( θ) LOW-LOW LOW-HIGH HIGH-HIGH θ (arcmin) θ (arcmin) RSD: non-relativistic GR µ 0 = 0.5 µ 0 = 1 Simpson et al 2013 & Benjamin et al 2013 θ (arcmin) f σ D WiggleZ - Blake et al 2012 & 6dfGRS Beutler et al z

22 Simpson, Heymans et al 2013

23 Atmospheric effects Heymans/Rowe et al 2012

24 Atmospheric effects Heymans/Rowe et al 2012 Chang et al 2012

25 LSST Simulation Chang et al 2012 CFHT short exposure Data Heymans et al 2012

26 Calibration dependent on both Resolution and SNR true =(1+m) obs

27 CFHTLenS Data release: Download now from sq degrees ugriz lensing quality reduced deep pixel data Combined Lensing Shear and Photometric redshift catalogues to i<24.7 Tomographic shear correlation functions, redshift distributions and covariance matrices MCMC chains available on request

28 Technical Heymans et al "CFHTLenS: The Canada- France-Hawaii Telescope Lensing Survey" Erben et al "CFHTLenS: The Canada-France- Hawaii Telescope Lensing Survey - Imaging Data and Catalogue Products" Miller et al "Bayesian Galaxy Shape Measurement for Weak Lensing Surveys -III. Application to CFHTLenS" Hildebrandt et al "CFHTLenS: improving the quality of photometric redshifts with precision photometry" Heymans & Rowe et al "The impact of high spatial frequency atmospheric distortions on weaklensing measurements" Cosmology Kilbinger et al "CFHTLenS: Combined Probe Cosmological Model Comparison using 2D Weak Gravitational Lensing" Simpson et al "CFHTLenS: Testing the Laws of Gravity with Tomographic Weak Lensing and Redshift Space Distortions" Benjamin et al "CFHTLenS tomographic weak lensing: Quantifying accurate redshift distributions" Heymans et al "CFHTLenS tomographic weak lensing cosmological parameter constraints: Mitigating the impact of intrinsic galaxy alignments" Van Waerbeke et al "CFHTLenS: Mapping the Large Scale Structures" Galaxy-galaxy Lensing Gillis et al "CFHTLenS: The Environmental Dependence of Galaxy Halo Masses from Weak Lensing" Simon et al "CFHTLenS: Higher-order galaxy-mass correlations probed by galaxy-galaxy-galaxy lensing" Velander et al "CFHTLenS: The Relation Between Galaxy Dark Matter Haloes and Baryons from Weak Gravitational Lensing"

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31 alternative slides!

32 m Planck

33 How intrinsically aligned the galaxy pairs are Heymans et al 2013

34 How aligned the galaxy pairs are Galaxy pair separation

35 low z, high z high z, high z How aligned the galaxy pairs are low z, low z Galaxy pair separation

36 CFHTLenS The state-of-the-art cosmological survey with 155 sq degrees, ugriz to i<24.7 (7σ extended source) Uses 5 yrs of data from the Deep, Wide and Pre-survey components of the CFHT Legacy Survey

37 GAMA-II VVDS Deep 64 sq degrees 22.5 sq degrees CFHTLS : 155 sq degrees 44 sq degrees 23 sq degrees VIPERS DEEP2 ugriz, to i=24.7 VVDS Wide Coupon et al 2010

38 Simpson, Heymans et al 2013 (a) µ(a) =µ 0 (a) = 0 (a)

39 Flat wcdm Curved wcdm Heymans et al 2013