论文标题
在精确弱透镜中形成噪声和分散
Shape noise and dispersion in precision weak lensing
论文作者
论文摘要
我们分析了Precision弱透镜（PWL）的第一个测量值：一种通过速度信息来测量单个Galaxy-galaxy弱透镜的新方法。我们的目标是了解PWL观察到的剪切分布，这比统计测量误差所能解释的要广泛。我们确定了两个可能的散射来源来解释观察到的分布：与圆形稳定旋转的基本假设相关的形状噪声项，以及与周围恒星至半径质量关系（SHMR）周围对数正态分散体一致的天体物理信号。我们已经将观察到的分布建模为这两个因素的组合，并量化了我们数据的最可能值。对于当前样本，我们测量的有效形状噪声为$σ_γ= 0.024 \ pm 0.007 $，强调了该方法的低噪声冲击，将PWL定位为$ \ sim 10 $ 10 $ 10 $ $倍于常规弱透镜。我们还测量了$ξ_γ= 0.53^{+0.26} _ { - 0.28} $ \，dex的平均剪切物的平均分散体。该测量值高于预期，这表明在光晕质量和/或轮廓中的分散体相对较高。
We analyse the first measurements from precision weak lensing (PWL): a new methodology for measuring individual galaxy-galaxy weak lensing through velocity information. Our goal is to understand the observed shear distribution from PWL, which is broader than can be explained by the statistical measurement errors. We identify two possible sources of scatter to explain the observed distribution: a shape noise term associated with the underlying assumption of circular stable rotation, and an astrophysical signal consistent with a log-normal dispersion around the stellar-to-halo mass relation (SHMR). We have modelled the observed distribution as the combination of these two factors and quantified their most likely values given our data. For the current sample, we measure an effective shape noise of $σ_γ= 0.024 \pm 0.007$, highlighting the low noise impact of the method and positioning PWL as $\sim 10$ times more precise than conventional weak lensing. We also measure an average dispersion in shears of $ξ_γ= 0.53^{+0.26}_{-0.28}$\,dex over the range of $8.5 < \log M_\star < 11$. This measurement is higher than expected, which is suggestive of a relatively high dispersion in halo mass and/or profile.
