利用强度干涉术测量强引力透镜类星体系统中的河外星系微透镜质量与运动
Measuring Extragalactic Microlens Masses and Motions in Strongly Lensed Quasar Systems with Intensity Interferometry
中文总结 AI 辅助
本研究提出结合流量比测光的强引力透镜类星体时间分辨强度干涉术，可打破传统微引力透镜的简并性，利用下一代干涉仪能高精度测量中等红移河外星系单个致密天体的质量与运动，还可区分恒星与暗物质微引力透镜。
中文摘要 AI 辅助
对遥远星系中单个恒星和致密天体的质量与横向运动进行直接测量仍是一项悬而未决的挑战，目前仅能通过依赖模型的种群拟合来约束河外星系恒星种群。我们表明，结合流量比测光的强引力透镜类星体的时间分辨强度干涉术，可打破传统光变曲线微引力透镜中源尺寸、微透镜质量与横向速度的简并性。以四重引力透镜类星体B1422+231为基准系统，利用下一代干涉仪（约800平方米集光面积、20000的光谱分辨率及皮秒级计时精度），我们预测了类星体源尺寸以及透镜星系中单个恒星质量微透镜的质量、位置与横向运动的测量精度。单周期观测在有利几何构型下可将吸积盘尺寸确定至4%（典型可探测构型下为10%），且对于m_l≥0.1M☉的微透镜，其质量可达到约1倍太阳质量的精度。为期8年共33个周期的观测 campaign 可将盘尺寸精度提升至≤1%，将微透镜的 impact 参数定位至约0.1-0.5微角秒，并可分辨其自行。此类观测将实现中等红移下单个河外星系致密天体质量与横向运动的直接测量，还可实现亚微角秒每年平方的光心加速度灵敏度，有助于区分恒星微引力透镜与暗物质子结构引力透镜，相关内容见配套论文。
英文摘要
The direct measurement of masses and transverse motions of individual stars and compact objects in distant galaxies remains an outstanding challenge, leaving extragalactic stellar populations constrained only through model-dependent population fits. We show that time-resolved intensity interferometry of strongly lensed quasars, combined with flux-ratio photometry, can break the source-size, microlens-mass, and transverse-velocity degeneracies of conventional light-curve microlensing. Using the quadruply lensed quasar B1422+231 as a fiducial system and a next-generation interferometer ($\sim$800\,m$^2$ collecting area, spectral resolving power of 20,000, and few-picosecond timing), we forecast the precision on the quasar source size and on the mass, position, and transverse motion of an individual stellar-mass microlens in the lens galaxy. A single epoch determines the accretion disk size to $4\%$ in favorable geometries ($10\%$ for a typical detectable configuration) and the microlens mass to order unity for $m_l \gtrsim 0.1\,M_\odot$. An eight-year, 33-epoch campaign reaches $\lesssim1\%$ on the disk size, localizes the microlens' impact parameter to $\sim0.1$-$0.5,μ\mathrm{as}$, and resolves its proper motion. Such observations would enable direct measurements of individual extragalactic compact-object masses and transverse motions at moderate redshift. They also yield sub-$μ\mathrm{as}\,\mathrm{yr}^{-2}$ sensitivity to light-centroid acceleration, which can help separate stellar microlensing from dark matter substructure lensing, the subject of a companion paper.
