发表机构
Leiden University; Shanghai Jiao Tong University; Max Planck Institute for Astrophysics（莱顿大学; 上海交通大学; 马克斯·普朗克天体物理学研究所）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
利用Euclid模拟数据，通过小尺度星系-星系弱透镜约束恒星质量，验证了Galfit去透镜光可显著降低偏差，并高精度限制IMF参数。
AI 中文摘要
小尺度星系-星系弱引力透镜通过约束星系内部物质分布，为探测恒星初始质量函数提供了一种独立途径。我们利用为类似DESI的亮星系巡天设计的真实模拟星表，预测了即将开展的\textit{Euclid}观测的潜力，该巡天预计覆盖\textit{Euclid}广域巡天约$9000\\,\mathrm{deg}^2$的面积。我们评估了前景透镜光的影响，它在源探测、测光和形状测量中引入了显著的尺度依赖偏差。使用\textsc{Galfit}减去透镜光后，在低至半光半径四倍的尺度上，这些偏差减少了近一个数量级。我们模拟了恒星质量在$9.5 \leq \log(M_*/h^{-2}M_\odot) \leq 11.5$之间的中心星系周围的预测透镜信号，投影距离为$10$到$100\\,h^{-1}\mathrm{kpc}$。由此产生的信噪比对于中等质量星系达到$\sim 150$。假设暗物质贡献为NFW轮廓，我们将恒星失配参数$\alpha$的约束精度提高到全样本约$8.5\\%$，大质量星系约$8.6\\%$。这些结果凸显了小尺度星系-星系弱引力透镜作为IMF以及星系中恒星与暗物质联系的稳健探针的潜力，可利用即将开展的\textit{Euclid}数据实现。
英文摘要
Small-scale galaxy-galaxy weak lensing provides an independent way to probe the stellar initial mass function by constraining the matter distribution within galaxies. We forecast the potential of upcoming \textit{Euclid} observations using realistic mock catalogues designed for a DESI-like Bright Galaxy Survey, which is expected to cover approximately $9000\,\mathrm{deg}^2$ of the \textit{Euclid} wide survey area. We assess the impact of foreground lens light, which introduces significant scale-dependent biases in source detection, photometry, and shape measurements. Subtracting the lens light with \textsc{Galfit} reduces these biases by nearly an order of magnitude at scales down to four times the half-light radius. We model the predicted lensing signal around central galaxies with stellar masses between $9.5 \leq \log(M_*/h^{-2}M_\odot) \leq 11.5$ over projected separations of $10$ to $100\,h^{-1}\mathrm{kpc}$. The resulting signal-to-noise ratios reach $\sim 150$ for intermediate-mass galaxies. Assuming an NFW profile for the dark matter contribution, we constrain the stellar mismatch parameter $α$ to a precision of approximately $8.5$ percent for the full sample and $8.6$ percent for massive galaxies. These results highlight the potential of small-scale galaxy--galaxy weak lensing as a robust probe of the IMF and the connection between stellar and dark matter in galaxies using upcoming \textit{Euclid} data.
Comments15 pages, 11 figures
