Evidence of the accelerated expansion of the Universe from weak lensing tomography with COSMOS

被引：290

作者：

Schrabback, T. ^{[1
,2
]}

Hartlap, J. ^{[2
]}

Joachimi, B. ^{[2
]}

Kilbinger, M. ^{[3
,4
,5
]}

Simon, P. ^{[6
]}

Benabed, K. ^{[3
,4
]}

Bradac, M. ^{[7
,8
]}

Eifler, T. ^{[2
,9
]}

Erben, T. ^{[2
]}

Fassnacht, C. D. ^{[7
]}

High, F. William ^{[10
]}

Hilbert, S. ^{[2
,11
]}

Hildebrandt, H. ^{[1
]}

Hoekstra, H. ^{[1
]}

Kuijken, K. ^{[1
]}

Marshall, P. J. ^{[8
,12
]}

Mellier, Y. ^{[3
,4
]}

Morganson, E. ^{[12
]}

Schneider, P. ^{[2
]}

Semboloni, E. ^{[1
,2
]}

Van Waerbeke, L. ^{[13
]}

Velander, M. ^{[1
]}

机构：

[1] Leiden Univ, Leiden Observ, NL-2333 CA Leiden, Netherlands

[2] Univ Bonn, Argelander Inst Astron, D-53121 Bonn, Germany

[3] CNRS, UMR 7095, Inst Astrophys Paris, F-75014 Paris, France

[4] UPMC, F-75014 Paris, France

[5] Shanghai Normal Univ, Shanghai Key Lab Astrophys, Shanghai 200234, Peoples R China

[6] Univ Edinburgh, Royal Observ, Sch Phys, Inst Astron,SUPA, Edinburgh EH9 3HJ, Midlothian, Scotland

[7] Univ Calif Davis, Dept Phys, Davis, CA 95616 USA

[8] Univ Calif Santa Barbara, Dept Phys, Santa Barbara, CA 93601 USA

[9] Ohio State Univ, Ctr Cosmol & AstroParticle Phys, Columbus, OH 43210 USA

[10] Harvard Univ, Dept Phys, Cambridge, MA 02138 USA

[11] Max Planck Inst Astrophys, D-85741 Garching, Germany

[12] KIPAC, Stanford, CA 94309 USA

[13] Univ British Columbia, Dept Phys & Astron, Vancouver, BC V6T 1Z1, Canada

来源：

ASTRONOMY & ASTROPHYSICS | 2010年 / 516卷

关键词：

cosmological parameters; dark matter; large-scale structure of Universe; gravitational lensing: weak; HUBBLE-SPACE-TELESCOPE; DARK-ENERGY CONSTRAINTS; INTRINSIC GALAXY ALIGNMENTS; SHEAR CORRELATION-FUNCTIONS; POINT-SPREAD FUNCTION; DIGITAL SKY SURVEY; PHOTOMETRIC REDSHIFTS; ADVANCED CAMERA; POWER SPECTRUM; COSMOLOGICAL CONSTRAINTS;

D O I：

10.1051/0004-6361/200913577

中图分类号：

P1 [天文学];

学科分类号：

0704 ;

摘要：

We present a comprehensive analysis of weak gravitational lensing by large-scale structure in the Hubble Space Telescope Cosmic Evolution Survey (COSMOS), in which we combine space-based galaxy shape measurements with ground-based photometric red-shifts to study the redshift dependence of the lensing signal and constrain cosmological parameters. After applying our weak lensing-optimized data reduction, principal-component interpolation for the spatially, and temporally varying ACS point-spread function, and improved modelling of charge-transfer inefficiency, we measured a lensing signal that is consistent with pure gravitational modes and no significant shape systematics. We carefully estimated the statistical uncertainty from simulated COSMOS-like fields obtained from ray-tracing through the Millennium Simulation, including the full non-Gaussian sampling variance. We tested our lensing pipeline on simulated space-based data, recalibrated non-linear power spectrum corrections using the ray-tracing analysis, employed photometric redshift information to reduce potential contamination by intrinsic galaxy alignments, and marginalized over systematic uncertainties. We find that the weak lensing signal scales with redshift as expected from general relativity for a concordance ACDM cosmology, including the full cross-correlations between different redshift bins. Assuming a flat ACDM cosmology, we measure sigma(8) (Omega(m)/0.3)(0.51) = 0.75 +/- 0.08 from lensing, in perfect agreement with WMAP-5, yielding joint constraints Omega(m) = 0.266(-0.023)(+ 0.025), sigma(8) = 0.802(-0.029+)(0.028) (all 68.3% conf.). Dropping the assumption of flatness and using priors from the HST Key Project and Big-Bang nucleosynthesis only, we find a negative deceleration parameter q(0) at 94.3% confidence from the tomographic lensing analysis, providing independent evidence of the accelerated expansion of the Universe. For a flat wCDM cosmology and prior w is an element of [- 2, 0], we obtain w < - 0.41 (90% conf.). Our dark energy constraints are still relatively weak solely due to the limited area of COSMOS. However, they provide an important demonstration of the usefulness of tomographic weak lensing measurements from space.

引用

页数：26

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