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arXiv 1408.2295astro-ph.COastro-ph.GA
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微分放大率的测量

Measurement of differential magnification

Xinzhong Er

摘要:

在引力透镜中,放大效应改变了背景星系的亮度和大小。如果图像尺寸与放大率和剪切变化的尺度相比并不小,则发生称为微分放大的高阶失真。我们给出了几种晕模型的放大率梯度的近似。假设一个对称分布的源亮度,估计微分放大率,然后进行模拟测试。我们估计的主要不确定性之一来自图像的有限分辨率。我们研究我们的方法的强度与当前和未来的望远镜的分辨率。我们指出,该方法是一种很有潜力的估算第一弯曲度的方法,可用于研究星系和星系团的质量分布。

英文摘要:

In gravitational lensing, the magnification effect changes the luminosity and size of a background galaxy. If the image sizes are not small compared to the scale over which the magnification and shear vary, higher-order distortions occur which are termed differential magnification. We give an approximation of the magnification gradient for several halo models. Assuming a symmetric distribution of source brightness, estimates for the differential magnification are obtained and then tested with simulations. One of the main uncertainties of our estimators comes from the finite resolution of the image. We study the strength of our method with the resolution of current and future telescopes. We point out that out method is a potential approach to estimate the first flexion, and can be used to study galaxy and cluster mass profiles.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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