论文标题
用爱因斯坦环测量视线剪切：概念证明
Measuring line-of-sight shear with Einstein rings: a proof of concept
论文作者
论文摘要
长期以来，强烈重力镜头的视线效应已被视为滋扰。但是，最近有人提出，如果镜头模型参数不归纳，那么视线剪切本身就可以自身可观察到。我们首先证明，可以从具有精度百分比的简单模拟的强镜图像中准确测量视线剪切。然后，我们将分析扩展到更复杂的模拟图像，并在使用不足的拟合模型时测试视线剪切的恢复，发现它从具有镜头模型参数的变性中逃脱了，尽管以精度为代价。最后，我们通过在存在许多视线暗物质光环的情况下模拟和拟合产生的图像来检查潮汐近似的有效性，发现明确违反了潮汐近似的行为并不一定会阻止一个人测量闪光的剪切剪切。
Line-of-sight effects in strong gravitational lensing have long been treated as a nuisance. However, it was recently proposed that the line-of-sight shear could be a cosmological observable in its own right, if it is not degenerate with lens model parameters. We firstly demonstrate that the line-of-sight shear can be accurately measured from a simple simulated strong lensing image with percent precision. We then extend our analysis to more complex simulated images and stress test the recovery of the line-of-sight shear when using deficient fitting models, finding that it escapes from degeneracies with lens model parameters, albeit at the expense of the precision. Lastly, we check the validity of the tidal approximation by simulating and fitting an image generated in the presence of many line-of-sight dark matter haloes, finding that an explicit violation of the tidal approximation does not necessarily prevent one from measuring the line-of-sight shear.
