引力透镜时间延迟研究进展  

Research progress on gravitational lensing time delays

作　　者：廖恺 Kai Liao(School of Physics and Technology,Wuhan University,Wuhan 430072,China)

机构地区：[1]武汉大学物理科学与技术学院,武汉430072

出　　处：《科学通报》2024年第1期80-95,共16页Chinese Science Bulletin

基　　金：国家自然科学基金(12222302,11973034)资助。

摘　　要：引力透镜效应是天文学研究经常用到的重要工具.这个效应中一个有趣的现象是同一天体源在某些情形下能够产生多个像.这些像依次到达地球并被人们观测到.它们之间的到达时间差称为时间延迟,携带着丰富的天文学信息.针对不同的天体源,人们发展出特定的观测策略和算法来测量时间延迟.传统的时间延迟观测源为透镜化的类星体.它们的时间延迟是通过对比光变曲线来测量的.在韦布望远镜时代,类星体时间延迟将给出准确的哈勃常数测量值,以期解决当前“哈勃常数争论”.同时,随着时域天文学时代的开启,透镜化的瞬变源,例如各类型的超新星、伽马射线暴及其余辉、快速射电暴和引力波也将被人们大量观测到.对于这些源,时间延迟测量有可能变得更加容易和准确.瞬变源透镜系统将带给我们更多关于引力本性、暗物质性质以及宇宙膨胀的信息.本文基于国内外在时间延迟领域的最新研究进展,介绍了时间延迟的测量方法、测量现状以及它在检验基础物理、研究天体物理和宇宙学方面的应用.According to Einstein's general relativity(GR),light travels along a null geodesic.Therefore,when the inhomogeneous distribution of matter leads to the curvature of time and space,light rays will deflect as the light deflects in the optical lens.This phenomenon is called“gravitational lensing”.The gravitational lensing effect is an important tool used in astronomical research.The history of gravitational lensing dates back to the observation of starlight deflection by the Sun during the solar eclipse in 1919 as strong evidences in favor of GR.A more interesting phenomenon in this effect is that the same celestial source can generate multiple images under certain circumstances.These images arrive on Earth in sequence and are observed by people.The difference in arrival time between them is called“time delay”and carries rich astronomical information.Specific observation strategies and algorithms have been developed to measure time delays for different celestial sources.In modern cosmology,the traditional time delay observation object is a distant bright quasar strongly lensed by the foreground galaxy or galaxy cluster,forming multiple magnified images of the point-like bright nucleus while the lensed dimmer parts of the host galaxy appear in the form of stretched arcs.Such lensed quasar systems have been attracting great attention as they are useful for efficient studies of either the nature of lens galaxies and quasars or the geometry of the Universe.Their time delay is measured by comparing the light variation curves.In the era of Webb telescope,the time delay of quasars will give accurate measurements of Hubble constant,in order to solve the current“Hubble constant issue”.Meanwhile,with the opening of the era of time-domain astronomy,lensed transient sources such as various types of supernovae,gamma ray bursts(GRBs)and their afterglow,rapid radio bursts(FRBs),and gravitational waves(GWs)will also be widely observed.For these sources,time delay measurement may become easier and more accurate.The trans

关 键 词：引力透镜 时间延迟 类星体 瞬变源 宇宙学 

分 类 号：P159[天文地球—天文学]