发表机构
University of Pennsylvania; Shanghai Jiao Tong University; Durham University; Lawrence Berkeley National Laboratory; Boston University; University of Edinburgh; Università degli Studi di Milano; INAF-Osservatorio Astronomico di Brera; University College London; Universidad de La Laguna (ULL); Instituto de Astrofísica de Canarias（宾夕法尼亚大学; 上海交通大学; 杜伦大学; 劳伦斯伯克利国家实验室; 波士顿大学; 爱丁堡大学; 米兰大学; 布拉腊天文台; 伦敦大学学院; 拉各纳大学; 加那利天体物理研究所）
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DESI亮红星系的基本平面尺寸残差进行谱学星系-星系透镜放大测量，标定放大偏差后恢复表面密度轮廓，提供了一种干净且互补的宇宙结构探针。
AI 中文摘要
弱引力透镜为描绘宇宙结构提供了有力途径，但当前大多数测量依赖于深场成像巡天中的星系形状畸变，并受到内禀取向、测光红移不确定性和形状测量偏差等系统效应的影响。在此，我们提出一种利用基本平面（FP）尺寸残差δ_r≡Δlog₁₀R_e的谱学星系-星系透镜放大测量，样本为DESI亮星系巡天透镜后方的326万个DESI亮红星系（LRG）源。FP类关系可利用透镜不变量（包括速度弥散σ₀和表面亮度I_e）预测LRG的内禀尺寸，其弥散约为0.06–0.07 dex。透镜放大效应会放大LRG的尺寸，给出直接会聚响应δ_r(κ)=κ/ln10，但我们表明，完整的透镜响应会受到放大偏差的修正，因为用I_e拟合R_e不可避免地会在平均尺寸残差δ̄_r(m)中引入星等依赖。在标定这一响应后，我们恢复的表面密度轮廓的不确定度可与使用500万至2000万个高红移源的单个Stage-III剪切巡天相当。相应的超额表面密度轮廓与基于剪切的测量结果一致。我们进一步表明，该估计量对尺寸测量不确定度具有稳健性，其会聚乘性偏差仅为尺寸偏差的约-0.2倍。因此，FP透镜提供了一种干净、谱学且互补的宇宙结构探针。
英文摘要
Weak gravitational lensing provides a powerful way to map cosmic structure, but most current measurements rely on galaxy shape distortions from deep imaging surveys and are affected by systematics such as intrinsic alignments, photometric-redshift uncertainties and shape-measurement biases. Here we present a spectroscopic galaxy-galaxy lensing magnification measurement using Fundamental-Plane (FP) size residuals, $δ_r\equivΔ\log_{10}R_\mathrm{e}$, from 3.26 million DESI luminous red galaxy (LRG) sources behind DESI Bright Galaxy Survey lenses. The FP-like relation predicts the intrinsic sizes of LRGs from lensing-invariant quantities, including velocity dispersion $σ_0$ and surface brightness $I_\mathrm{e}$, with a scatter of about 0.06-0.07 dex. Lensing magnifies LRG sizes, giving the direct convergence response $δ_r(κ)=κ/\ln 10$, but we show that the full lensing response is modified by magnification bias, because fitting $R_\mathrm{e}$ with $I_\mathrm{e}$ inevitably induces a magnitude dependence in $\barδ_r(m)$. After calibrating this response, we recover surface-density profiles with uncertainties comparable to those from individual Stage-III shear surveys using 5-20 million higher-redshift sources. The corresponding excess surface-density profiles agree with shear-based measurements. We further show that the estimator is robust to size-measurement uncertainties, with a convergence multiplicative bias only $\simeq -0.2$ times the size bias. FP lensing therefore provides a clean, spectroscopic and complementary probe of cosmic structure.
Comments22 pages, 5+4 figures, submitted
