Статья

The WiggleZ Dark Energy Survey: direct constraints on blue galaxy intrinsic alignments at intermediate redshifts

Rachel MandelbaumDepartment of Astrophysical Sciences, Princeton University, Peyton Hall, Princeton NJ 08544, USAChris BlakeCentre for Astrophysics & Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, AustraliaSarah BridleDepartment of Physics and Astronomy, University College London, Gower Street, London WC1E 6BTF. B. AbdallaDepartment of Physics and Astronomy, University College London, Gower Street, London WC1E 6BTSarah BroughAnglo-Australian Observatory, PO Box 296, Epping, NSW 2121, AustraliaMatthew CollessAnglo-Australian Observatory, PO Box 296, Epping, NSW 2121, AustraliaW. J. CouchCentre for Astrophysics & Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, AustraliaS. M. CroomSchool of Physics, University of Sydney NSW 2006, AustraliaT. M. DavisDepartment of Physics, University of Queensland, Brisbane, QLD 4072, AustraliaM. J. DrinkwaterDepartment of Physics, University of Queensland, Brisbane, QLD 4072, AustraliaKarl FörsterCalifornia Institute of Technology, MC 405-47, 1200 East California Boulevard, Pasadena, CA 91125, USAKarl GlazebrookCentre for Astrophysics & Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, AustraliaBen JelliffeSchool of Physics, University of Sydney NSW 2006, AustraliaRussell J. JurekDepartment of Physics, University of Queensland, Brisbane, QLD 4072, AustraliaI-hui LiCentre for Astrophysics & Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, AustraliaBarry F. MadoreObservatories of the Carnegie Institute of Washington, 813 Santa Barbara St, Pasadena, CA 91101, USAChris MartinCalifornia Institute of Technology, MC 405-47, 1200 East California Boulevard, Pasadena, CA 91125, USAKevin A. PimbbletSchool of Physics Monash University Clayton Vic 3800 AustraliaGregory B. PooleCentre for Astrophysics & Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, AustraliaMichael PracyResearch School of Astronomy & Astrophysics, Australian National University, Weston Creek, ACT 2600, AustraliaR. SharpAnglo-Australian Observatory, PO Box 296, Epping, NSW 2121, AustraliaEmily WisnioskiCentre for Astrophysics & Supercomputing, Swinburne University of Technology, PO Box 218, Hawthorn, VIC 3122, AustraliaDavid WoodsDepartment of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, B.C. V6T 1Z1, CanadaTed WyderCalifornia Institute of Technology, MC 405-47, 1200 East California Boulevard, Pasadena, CA 91125, USA

2010en

ABI

Аннотация

Correlations between the intrinsic shapes of galaxy pairs, and between the intrinsic shapes of galaxies and the large-scale density field, may be induced by tidal fields. These correlations, which have been detected at low redshifts (z<0.35) for bright red galaxies in the Sloan Digital Sky Survey (SDSS), and for which upper limits exist for blue galaxies at z~0.1, provide a window into galaxy formation and evolution, and are also an important contaminant for current and future weak lensing surveys. Measurements of these alignments at intermediate redshifts (z~0.6) that are more relevant for cosmic shear observations are very important for understanding the origin and redshift evolution of these alignments, and for minimising their impact on weak lensing measurements. We present the first such intermediate-redshift measurement for blue galaxies, using galaxy shape measurements from SDSS and spectroscopic redshifts from the WiggleZ Dark Energy Survey. Our null detection allows us to place upper limits on the contamination of weak lensing measurements by blue galaxy intrinsic alignments that, for the first time, do not require significant model-dependent extrapolation from the z~0.1 SDSS observations. Also, combining the SDSS and WiggleZ constraints gives us a long redshift baseline with which to constrain intrinsic alignment models and contamination of the cosmic shear power spectrum. Assuming that the alignments can be explained by linear alignment with the smoothed local density field, we find that a measurement of sigma_8 in a blue-galaxy dominated, CFHTLS-like survey would be contaminated by at most +/-0.02 (95% confidence level, SDSS and WiggleZ) or +/-0.03 (WiggleZ alone) due to intrinsic alignments. [Abridged]

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Идентификаторы

DOI: 10.1111/j.1365-2966.2010.17485.x

Цитирования и источники

Цитирований: 1Использованных источников: 0

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