AI 中文总结
研究双源平面引力透镜系统中类星体光线受前景星系致密质量影响的“微引力透镜的微引力透镜效应”，通过数值模拟构建放大图，发现其焦散特征更复杂，体现在预期光变曲线上。
AI 中文摘要
微引力透镜，即星系引力透镜内恒星的影响，已成为探测致密质量的有力手段，并通过微分放大作用探测宇宙学距离上的亚秒差距尺度源。最近发现的一个双源平面引力透镜系统，其中最遥远的源是一个类星体，提供了复合微引力透镜的前景，即类星体光线受两个前景透镜星系内致密质量的影响。在此，我们展示了这种“微引力透镜的微引力透镜效应”的首次数值模拟。我们将最近发现的“爱因斯坦之字形”透镜J1721 + 8842作为基准案例，为该系统中的六个类星体图像构建微引力透镜放大图。由于众多初始微图像的二次微引力透镜效应，所得地图包含比单平面微引力透镜情况下更复杂的焦散特征，这反映在每个图像的预期光变曲线上。
英文摘要
Microlensing, the influence of stars within a galactic gravitational lens, has emerged as a powerful probe of compact mass and, through differential magnification, sub-parsec scale sources at cosmological distances. The recent discovery of a double-source-plane gravitational lens system in which the most distant source is a quasar offers the prospect of compound microlensing, in which quasar light rays are influenced by compact masses within the two foreground lensing galaxies. Here, we present the first numerical simulations of this "microlensing of microlensing". We consider the recently discovered "Einstein zig-zag" lens, J1721+8842, as a fiducial case, and construct microlensing magnification maps for each of the six quasar images in this system. Due to the secondary microlensing effects of the myriad of initial microimages, the resulting maps contain more complex caustic features than seen in the case of single plane microlensing. This is reflected in the expected lightcurves seen for each of the images.
Comments11 pages, 7 figures, accepted to MNRAS
