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S.N. Floor (University of Kanas), A.E. Evrard (University of Michigan)
By providing mass estimates of galaxy clusters that do not rely on dynamical assumptions, weak gravitational lensing is a technique that complements mass estimates from traditional X-ray and optical methods. Employing a typical thin-lens approximation on sight lines sampling approximately 7,000 massive (M200 > 3x1014 Msun h-1), intermediate redshift (0.3 < z < 1) halos drawn from sky survey output of a LCDM Hubble Volume simulation, we examine the accuracy of weak lensing mass estimates. For a source galaxy population lying near or beyond z ~1.5, we find that the simplest estimator based on the mean convergence within r200 yields masses that are biased high by ~30 percent, with a dispersion ~40 percent. We show that the bias, which is consistent in amplitude with previous estimates derived from smaller simulated samples, arises from correlated mass lying within 50 Mpc h-1 of the halo center while the variance arises from mass lying at larger distances along the line of sight. We find that the errors in estimated mass are only weakly dependent on halo mass and redshift, and are insensitive to halo orientation, suggesting that these error estimates will not depend strongly on cluster sample selection.
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Bulletin of the American Astronomical Society, 36 5
© 2004. The American Astronomical Society.