发表机构
School of Physics and Astronomy, Beijing Normal University（北京师范大学物理学院）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出利用宽分离透镜类星体的光谱差分红移测量运动透镜效应，以SDSS J1004+4112为例，蒙特卡洛预测显示在ELT配置下可达到10^-7精度，验证了该方法的可行性。
AI 中文摘要
引力势的横向运动会引起穿过其中的光子频率偏移，从而产生运动透镜效应，并为横向本动速度提供探测手段。最近，利用宇宙微波背景温度图与大尺度结构示踪体之间的互相关，已报道了该效应的统计证据。在此，我们研究一种基于宽分离透镜类星体的互补光谱方法，对于此类天体，不同的透镜像通过运动的前景透镜探测不同的偏折几何。我们聚焦于SDSS J1004+4112，并评估可从其宽发射线光谱中测得的差分红移。利用一种结合线轮廓信息的估计器，我们在类ELT配置下对C IV和C III]进行了蒙特卡洛预测，仅考虑光子噪声。对于假设的透镜横向速度$500\\,{\rm km\\,s^{-1}}$以及使信号最大化的取向，预期差分红移达到$|\Delta z_{\rm ML}|\simeq6.7\times10^{-7}$。在40小时的积分时间下，联合光子噪声限制的精度为$\sigma_z\simeq2.5\times10^{-7}$。C IV主导约束，而C III]仅提供适度的额外改进，数十小时的积分可达到$10^{-7}$精度量级。这些结果表明，仅光子统计就能达到特征运动透镜信号尺度，尽管实际可探测性将取决于对天体物理和仪器系统误差的控制。
英文摘要
The transverse motion of a gravitational potential induces frequency shifts in photons propagating through it, giving rise to the moving-lens effect and providing a probe of transverse peculiar velocities. Statistical evidence for this effect has recently been reported using cross-correlations between cosmic microwave background temperature maps and large-scale-structure tracers. Here, we investigate a complementary spectroscopic approach based on wide-separation lensed quasars, for which different lensed images probe distinct deflection geometries through a moving foreground lens. We focus on SDSS J1004+4112 and assess the differential redshift that could be measured from its broad emission-line spectra. Using an estimator that combines information across the line profiles, we perform Monte Carlo forecasts for C IV and C III] under an ELT-like configuration, considering photon noise only. For an assumed lens transverse velocity of $500\,{\rm km\,s^{-1}}$ and the orientation maximizing the signal, the expected differential redshift reaches $|Δz_{\rm ML}|\simeq6.7\times10^{-7}$. At an integration time of 40 hr, the joint photon-noise-limited precision is $σ_z\simeq2.5\times10^{-7}$. C IV dominates the constraint, while C III] provides only a modest additional improvement, and integrations of tens of hours reach the $10^{-7}$ precision regime. These results show that photon statistics alone can reach the characteristic moving-lens signal scale, although practical detectability will depend on controlling astrophysical and instrumental systematics.
Comments9 pages, 5 figures
