标题： 平方公里阵列的微引力透镜和强引力透镜：高红移星系中致密天体的质量函数 显示英文标题

标题： Micro & strong lensing with the Square Kilometer Array: The mass--function of compact objects in high--redshift galaxies

摘要： 我们展示了近期对CLASS引力透镜B1600+434进行的VLA 8.5-GHz和WSRT 1.4及4.9-GHz监测活动的结果，并表明观测到的变化强烈支持暗物质主导的边缘盘星系晕中的MACHOs微透镜效应，该星系位于z=0.4处。 被平方公里阵列探测到的具有微焦耳量级流量密度的平坦光谱射电源预计尺寸为微角秒量级。 因此，它们会由于银河闪烁（衍射和折射）而快速变化。 然而，当它们位于遥远星系后方时，也会因微透镜效应而表现出变化，甚至比B1600+434的情况更为显著。 这些背景源中的相对论或超光速运动通常会导致几天到几周的时间尺度上的时间变化。 通过不同的特征时间尺度和调制的频率依赖性，可以区分并分离出闪烁和微透镜效应。 因此，平方公里阵列在GHz频段的监测研究将探测暗物质及其质量函数的微观和宏观性质随红移的变化，这种信息很难通过其他方法获得。 显示英文摘要

摘要： We present the results from recent VLA 8.5-GHz and WSRT 1.4 and 4.9-GHz monitoring campaigns of the CLASS gravitational lens B1600+434 and show how the observed variations argue strongly in favor of microlensing by MACHOs in the halo of a dark-matter dominated edge-on disk galaxy at z=0.4. The population of flat-spectrum radio sources with micro-Jy flux-densities detected with the Square-Kilometer-Array is expected to have dimensions of micro-arcsec. They will therefore vary rapidly as a result of Galactic scintillation (diffractive and refractive). However, when positioned behind distant galaxies they will also show variations due to microlensing, even more strongly than in the case of B1600+434. Relativistic or superluminal motion in these background sources typically leads to temporal variations on time scales of days to weeks. Scintillation and microlensing can be distinguished, and separated, by their different characteristic time scales and the frequency dependence of their modulations. Monitoring studies with Square-Kilometer-Array at GHz frequencies will thus probe both microscopic and macroscopic properties of dark matter and its mass-function as a function of redshift, information very hard to obtain by any other method.