Mass Bias of Weak Lensing Shear-selected Galaxy Cluster Samples

Understand

We estimate the bias on weak lensing mass measurements of shear-selected galaxy cluster samples.

• The mass bias is expected to be significant because constructions of cluster samples from peaks in weak lensing mass maps and measurements of cluster masses from their tangential shear profiles share the same noise.
• We quantify this mass bias from large sets of mock cluster samples with analytical density profiles and realistic large-scale structure noise from ray-tracing simulations.
• We find that, even for peaks with signal-to-noise ratio larger than $4.0$ in weak lensing mass maps constructed in a deep survey with a high source galaxy number density of $30~\mathrm{arcmin}^{-2}$, derived weak lensing masses for these shear-selected clusters are still biased high by $\sim55\%$ on average.