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Weak Lensing from Space II: Dark Matter Mapping

Richard Massey·Jason Rhodes·Alexandre Refregier·Justin Albert·David Bacon·Gary Bernstein·Richard Ellis·Bhuvnesh Jain·Tim McKay·Saul Perlmutter·Andy Taylor
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Abstract

We study the accuracy with which weak lensing measurements could be made from a future space-based survey, predicting the subsequent precisions of 3-dimensional dark matter maps, projected 2-dimensional dark matter maps, and mass-selected cluster catalogues. As a baseline, we use the instrumental specifications of the Supernova/Acceleration Probe (SNAP) satellite. We first compute its sensitivity to weak lensing shear as a function of survey depth. Our predictions are based on detailed image simulations created using `shapelets', a complete and orthogonal parameterization of galaxy morphologies. We incorporate a realistic redshift distribution of source galaxies, and calculate the average precision of photometric redshift recovery using the SNAP filter set to be Delta z=0.034. The high density of background galaxies resolved in a wide space-based survey allows projected dark matter maps with a rms sensitivity of 3% shear in 1 square arcminute cells. This will be further improved using a proposed deep space-based survey, which will be able to detect isolated clusters using a 3D lensing inversion techniques with a 1 sigma mass sensitivity of approximately 10^13 solar masses at z~0.25. Weak lensing measurements from space will thus be able to capture non-Gaussian features arising from gravitational instability and map out dark matter in the universe with unprecedented resolution.

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Richard Massey, Jason Rhodes, Alexandre Refregier, Justin Albert, David Bacon, Gary Bernstein, Richard Ellis, Bhuvnesh Jain, Tim McKay, Saul Perlmutter, Andy Taylor. 2004-03-12. Weak Lensing from Space II: Dark Matter Mapping. https://doi.org/10.1086/420985

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