2003/12/10 by Jason Rhodes, Alexandre Refregier, Nicholas R. Collins +3 · 1 citation
Physics and Astronomy · #Cosmology and Gravitation Theories #Dark Matter and Cosmic Phenomena #Galaxies: Formation, Evolution, Phenomena #astro-ph
paper · pdf · doi:10.1086/382181
published as Astrophys.J. 605 (2004) 29-36 · 9 pages, 5 figure, 1 table, Accepted to ApJ
arxiv created 2003/12/10 · openalex publication_date 2004/04/07 · arxiv updated 2009/12/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
Weak lensing by large-scale structure allows a direct measure of the dark matter distribution. We have used parallel images taken with the Space Telescope Imaging Spectrograph (STIS) on the Hubble Space Telescope to measure weak lensing, or cosmic shear. We measure the shapes of 26,036 galaxies in 1292 STIS fields and measure the shear variance at a scale of 0 51. The charge transfer efficiency (CTE) of STIS has degraded over time and introduces a spurious ellipticity into galaxy shapes during the readout process. We correct for this effect as a function of signal-to-noise ratio and CCD position. We further show that the detected cosmic shear signal is nearly constant in time over the approximately 4 yr of observation. We detect cosmic shear at the 5.1 σ level, and our measurement of the shear variance is consistent with theoretical predictions in a ΛCDM universe. This provides a measure of the normalization of the mass power spectrum σ 8 = 0.46 0.18 . The 1 σ error includes noise, cosmic variance, systematics, and the redshift uncertainty of the source galaxies. This is consistent with previous cosmic shear measurements, but tends to favor those with a high value of σ 8 . It is also consistent with the recent determination of σ 8 from the Wilkinson Microwave Anisotropy Probe ( WMAP ) experiment.