Cosmological weak lensing and dark matter mapping with the Hubble Space Telescope

Tim Schrabback, Patrick Simon, Thomas Erben, Peter Schneider, Jan Hartlap, Catherine Heymans, Phil Marshall, Hendrik Hildebrandt, Chris Fassnacht, Eric Morganson, Maruša Bradač, Marco Hetterscheidt, Tim Eifler, Joan Marc Miralles, Jörg Dietrich, Robert Fosbury, Wolfram Freudling, Norbert Pirzkal

Research output: Chapter in Book/Report/Conference proceedingConference contribution

Abstract

Cosmological weak lensing, the gravitational lensing effect of large-scale structure, provides a unique tool to study the large-scale matter distribution and constrain the power spectrum of matter fluctuations free of assumptions on the relation between luminous and dark matter. Due to the weakness of cosmological shear, it can only be detected statistically requiring accurate correction for systematic effects, most importantly the image point-spread-function. Here we present results from our cosmological weak lensing analysis of archival data from the Advanced Camera for Surveys on board the Hubble Space Telescope. Compared to ground-based observations the excellent resolution obtained from space provides a much higher number density of resolved galaxies which can be used to extract the shear signal. This enables us to locally suppress the shape noise induced by the intrinsic ellipticities of galaxies, which is particularly useful for dark matter mapping and constraining the small-scale power spectrum. We have already completed a pilot study using early data from the ACS Parallel Cosmic Shear Survey and the combined GEMS and GOODS mosaic of the Chandra Deep Field South (CDFS). From the low shear signal detected in the GEMS/GOODS data we conclude that this field is subject to strong sampling variance, with an exceptional under-density in its foreground. In a preliminary analysis of the HST/COSMOS Survey we detect residual systematics at small angular scales, whose origin is currently been investigated. Using only B-mode-free scales we find a preliminary estimate for the normalisation of the matter fluctuation power spectrum σ8 = 0.71 ± 0.09 (68% confidence) for a matter density Ωm = 0.24, where the error includes the uncertainties in the redshift distribution, the Hubble constant, and the shear calibration, as well as a Gaussian estimate for cosmic variance.

Original languageEnglish (US)
Title of host publicationProceedings of the 6th International Heidelberg Conference on Dark Matter in Astroparticle and Particle Physics, Dark 2007
PublisherWorld Scientific Publishing Co. Pte Ltd
Pages260-273
Number of pages14
ISBN (Print)9812814345, 9789812814340
DOIs
StatePublished - Jan 1 2008
Externally publishedYes
Event6th International Heidelberg Conference on Dark Matter in Astro and Particle Physics, Dark 2007 - Sydney, NSW, Australia
Duration: Sep 24 2007Sep 28 2007

Publication series

NameProceedings of the 6th International Heidelberg Conference on Dark Matter in Astroparticle and Particle Physics, Dark 2007

Conference

Conference6th International Heidelberg Conference on Dark Matter in Astro and Particle Physics, Dark 2007
CountryAustralia
CitySydney, NSW
Period9/24/079/28/07

Keywords

  • Cosmology
  • Gravitational lensing
  • Large-scale structure

ASJC Scopus subject areas

  • Astronomy and Astrophysics

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  • Cite this

    Schrabback, T., Simon, P., Erben, T., Schneider, P., Hartlap, J., Heymans, C., Marshall, P., Hildebrandt, H., Fassnacht, C., Morganson, E., Bradač, M., Hetterscheidt, M., Eifler, T., Miralles, J. M., Dietrich, J., Fosbury, R., Freudling, W., & Pirzkal, N. (2008). Cosmological weak lensing and dark matter mapping with the Hubble Space Telescope. In Proceedings of the 6th International Heidelberg Conference on Dark Matter in Astroparticle and Particle Physics, Dark 2007 (pp. 260-273). (Proceedings of the 6th International Heidelberg Conference on Dark Matter in Astroparticle and Particle Physics, Dark 2007). World Scientific Publishing Co. Pte Ltd. https://doi.org/10.1142/9789812814357_0026