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arXiv · 0912.2364

SHELS: Testing Weak Lensing Maps with Redshift Surveys

Margaret J. Geller·Michael J. Kurtz·Ian P. Dell'Antonio·Massimo Ramella·Daniel G. Fabricant
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Abstract

Weak lensing surveys are emerging as an important tool for the construction of "mass selected" clusters of galaxies. We evaluate both the efficiency and completeness of a weak lensing selection by combining a dense, complete redshift survey, the Smithsonian Hectospec Lensing Survey (SHELS), with a weak lensing map from the Deep Lens Survey (DLS). SHELS includes 11,692 redshifts for galaxies with R < 20.6 in the four square degree DLS field; the survey is a solid basis for identifying massive clusters of galaxies with redshift z < 0.55. The range of sensitivity of the redshift survey is similar to the range for the DLS convergence map. Only four the twelve convergence peaks with signal-to-noise > 3.5 correspond to clusters of galaxies with M > 1.7 x 10^14 solar masses. Four of the eight massive clusters in SHELS are detected in the weak lensing map yielding a completeness of roughly 50%. We examine the seven known extended cluster x-ray sources in the DLS field: three can be detected in the weak lensing map, three should not be detected without boosting from superposed large-scale structure, and one is mysteriously undetected even though its optical properties suggest that it should produce a detectable lensing signal. Taken together, these results underscore the need for more extensive comparisons among different methods of massive cluster identification.

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Margaret J. Geller, Michael J. Kurtz, Ian P. Dell'Antonio, Massimo Ramella, Daniel G. Fabricant. 2009-12-11. SHELS: Testing Weak Lensing Maps with Redshift Surveys. https://doi.org/10.1088/0004-637x%2F709%2F2%2F832

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