Publications of the Astronomical Society of Australia (PASA), Vol. 32, e040, 16 pages (2015). C Astronomical Society of Australia 2015; published by Cambridge University Press. doi:10.1017/pasa.2015.39 Direct Shear Mapping: Prospects for Weak Lensing Studies of Individual Galaxy–Galaxy Lensing Systems C. O. de Burgh-Day1,2,3,4, E. N. Taylor1,3,R.L.Webster1,3 and A. M. Hopkins2,3 1School of Physics, David Caro Building, The University of Melbourne, Parkville VIC 3010, Australia 2The Australian Astronomical Observatory, PO Box 915, North Ryde NSW 1670, Australia 3ARC Centre of Excellence for All-sky Astrophysics (CAASTRO), School of Physics, David Caro Building, The University of Melbourne, Parkville VIC 3010, Australia 4Email:
[email protected] (Received April 23, 2012; Accepted September 21, 2012) Abstract Using both a theoretical and an empirical approach, we have investigated the frequency of low redshift galaxy-galaxy lensing systems in which the signature of 3D weak lensing might be directly detectable. We find good agreement between these two approaches. Using data from the Galaxy and Mass Assembly redshift survey we estimate the frequency of detectable weak lensing at low redshift. We find that below a redshift of z ∼ 0.6, the probability of a galaxy being weakly γ ≥ . ∼ . − lensed by 0 02 is 0 01. We have also investigated the feasibility of measuring the scatter in the M∗ Mh relation using shear statistics. We estimate that for a shear measurement error of γ = 0.02 (consistent with the sensitivity of the Direct Shear Mapping technique), with a sample of ∼50,000 spatially and spectrally resolved galaxies, the scatter in the − M∗ Mh relation could be measured.