First Cosmic Shear Results from the Canada-France-Hawaii Telescope Wide Synoptic Legacy Survey

By H. Hoekstra, Y. Mellier, L. Waerbeke, E. Semboloni, L. Fu, M. Hudson, Laura C. Parker, Ismael Tereno, K. Benabed. 2005

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We present the first measurements of the weak gravitational lensing signal induced by the large-scale mass distribution in the universe from data obtained as part of the ongoing Canada-France-Hawaii Telescope Legacy Survey (CFHTLS). The data used in this analysis are from the Wide Synoptic Survey, which aims to image ~170 deg2 in five filters. We have analyzed an effective area of ~22 deg2 (31 pointings) of i′ data spread over two of the three survey fields. These data are of excellent quality, and the results bode well for the remainder of the survey: we do not detect a significant "B" mode, suggesting that residual systematics are negligible at the current level of accuracy. Assuming a cold dark matter model and marginalizing over the Hubble parameter h ∈ [0.6, 0.8], the source redshift distribution, and systematics, we constrain σ8, the amplitude of the matter power spectrum. At a fiducial matter density Ωm = 0.3 we find σ8 = 0.85 ± 0.06. This estimate is in excellent agreement with previous studies. A combination of our results with those from the Deep component of the CFHTLS enables us to place a constraint on a constant equation of state for the dark energy, based on cosmic shear data alone. We find that w0 < -0.8 at 68% confidence.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/f136de696f03fd5fd3fd5c5986bf4d218f1e3700

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Citations in the corpus

Calibrating Redshift Distributions beyond Spectroscopic Limits with Cross-Correlations (2008, background): “…photometric dark energy probes such as the Large Synoptic Survey Telescope (LSST; Tyson & Angel 2001; Tyson 2005) or the Supernova / Acceleration Probe (SNAP; Deustua et al. 2000; Perlmutter & SNAP 2004), or even the millions of faint galaxies in samples now underway (Hoekstra et al. 2006).”
Optimal Surveys for Weak Lensing Tomography (2006, background): “Current cosmic shear measurements typically cover areas of a few to a few tens of square degrees (Massey et al. 2004a; Heymans et al. 2004; Rhodes et al. 2004; Hoekstra et al. 2006; Semboloni et al. 2006) and are able to measure the amplitude of the matter power-spectrum to an accuracy of ∼ 10%.”
Constraints on intrinsic alignment contamination of weak lensing surveys using the MegaZ-LRG sample (2010, methodology): “Shape noise is incorporated with an overall galaxy number density ofnΩ = 12 arcmin−2 and a dispersion of the absolute value of the complex intrinsic ellipticity of 0.3 (Hoekstra et al. 2006).”
Scrutinizing Exotic Cosmological Models Using ESSENCE Supernova Data Combined with Other Cosmological Probes (2007, background): “The weak lensing data from the Canada-France-Hawaii Telescope (CFHT Hoekstra et al. 2006) is an additional source of data that we have omitted here.”
Cosmological constraints from the 100-deg2 weak-lensing survey (2007, methodology): “0.0 zp 4.0 0.2 zp 1.5 Equation (10) Equation (11) Equation (10) Equation (11) β α β α β α β α CFHTLS-Wide 0.84 ± 0.06 0.55 0.81 ± 0.07 0.54 0.86 ± 0.06 0.56 0.84 ± 0.06 0.55 GaBoDS 0.93 ± 0.08 0.60 0.89 ± 0.09 0.59 1.01 ± 0.09 0.66 0.98 ± 0.10 0.63 Smith et al. (2003) RCS 0.75 ± 0.07 0.55 0.73 ± 0.0”
A comparison of weak-lensing masses and X-ray properties of galaxy clusters (2007, background): “…the measurement of the lensing signal caused by large-scale structure (cosmic shear) has demonstrated the reliability with which the tiny distortions in the images of faint galaxies can be measured (e.g. Hoekstra, Yee & Gladders 2002b; van Waerbeke, Mellier & Hoekstra 2005; Hoekstra et al. 2006).”
The WiggleZ Dark Energy Survey: Direct constraints on blue galaxy intrinsic alignments at intermediate redshifts (2009, methodology): “…applications include measurement of the amplitude of matter fluctuations using the auto-correlation of galaxy shapes (e.g., most recently, Hoekstra et al. 2006; Semboloni et al. 2006; Benjamin et al. 2007; Massey et al. 2007b; Schrabback et al. 2009), known as cosmic shear; and…”
The Shear TEsting Programme 2: Factors affecting high precision weak lensing analyses (2006, methodology): “Hoekstra et al. (2006) also featured a parallel analysis using an independent KSB+ pipeline, which agreed with the HH results, and also demonstrates the potential robustness of KSB+ at this level of precision (similar comparisons have also been performed by Massey et al. (2005) and Schrabback et…”
Quantifying the effect of baryon physics on weak lensing tomography (2011, methodology): “The cosmic shear signal has been measured using large ground-based surveys (e.g., Hoekstra et al. 2006; Fu et al. 2008) and from space (e.g., Massey et al. 2007; Schrabback et al. 2010).”
Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Implications for Cosmology (2006, unknown): “…al. 2005); much larger samples of highredshift supernova (Riess et al. 2004; Astier et al. 2005; Nobili et al. 2005; Clocchiatti et al. 2006; Krisciunas et al. 2005); and significant improvements in the lensing data (Refregier 2003; Heymans et al. 2005; Semboloni et al. 2006; Hoekstra et al. 2006).”
CFHTLenS: the Canada–France–Hawaii Telescope Lensing Survey – imaging data and catalogue products (2012, methodology): “The first weak lensing analysis of the CFHTLS-Wide (Hoekstra et al. 2006) analysed 31 square degrees of single band i′ data, showing the high quality imaging obtained by the then newly commissioned one square degree field of view MegaCam imager on the 3.6m CFHT.”
Weak Gravitational Lensing with COSMOS: Galaxy Selection and Shape Measurements (2007, background): “…Hoekstra et al. 2004; Sheldon et al. 2004; Mandelbaum et al. 2006), and to put constraints on the matter density parameter m and the amplitude of thematter power spectrum 8 (e.g.,Hoekstra et al. 2006; Semboloni et al. 2006; Schrabback et al. 2006; Hetterscheidt et al. 2006; Jarvis et al. 2006).”
Very weak lensing in the CFHTLS Wide: Cosmology from cosmic shear in the linear regime (2007, methodology): “These early CFHTLS cosmic shear data were used by Semboloni et al. (2006) and Hoekstra et al. (2006) to derive constraints onΩm-σ8 and by Schimd et al. (2007) to explore some physical models of dark energy.”
Strong-lensing optical depths in a ΛCDM universe – II. The influence of the stellar mass in galaxies (2007, background): “Surveys measuring the weak lensing effects of the matter distribution as a whole (e.g. Semboloni et al. 2006; Hoekstra et al. 2006; Simon et al. 2007; Massey et al. 2007a; Benjamin et al. 2007; Fu et al. 2008) are particularly promising for further constraining the parameters of the ΛCDM model.”
CFHTLenS: combined probe cosmological model comparison using 2D weak gravitational lensing (2012, methodology): “…analyses of the CFHTLS used the first data release (T0001) with 4 deg2 of the Deep survey (Semboloni et al. 2005) and 22 deg2 of the Wide part of the survey (Hoekstra et al. 2006), followed by the third data release (T0003) comprising 55 deg2 (Benjamin et al. 2007; Fu et al. 2008, hereafter F08).”