发表机构
Peking University; Kavli Institute for Astronomy and Astrophysics, Peking University; Tsung-Dao Lee Institute, and Shanghai Key Laboratory for Particle Physics and Cosmology, Shanghai Jiao Tong University; Department of Astronomy, School of Physics and Astronomy, Shanghai Jiao Tong University（北京大学; 北京大学天文与天体物理喀维略研究所; 上海交大李政道研究所和粒子物理与宇宙学上海市重点实验室，上海交通大学; 上海交通大学物理与天文学院天文学系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文提出条件扩散模型，从SDSS星系恒星质量场重建投影暗物质场，在CAMELS训练、IllustrisTNG300-1验证，重建结果与真实值吻合，并发布覆盖90×90 (h⁻¹Mpc)²的公开暗物质图。
AI 中文摘要
暗物质设定了星系形成和演化的引力环境，但无法被直接观测。我们提出了一种条件扩散模型，该模型从星系恒星质量密度场重建投影暗物质密度场，可直接应用于星系巡天。该模型在CAMELS上训练，并在独立的IllustrisTNG300-1模拟上验证。从重建的投影孔径测量推断出的暗物质晕质量与相应的真实值吻合良好，散布低于0.2 dex。在100 kpc尺度上，重建的面密度在与观测最相关的区域显示出约0.3 dex的典型散布。我们将该模型应用于一个连续低红移区域中恒星质量$M_\star\ge10^9\\,M_\odot$的SDSS星系。通过对100个随机实现取平均，我们重建并公开发布了一个覆盖$90\times90\\,(h^{-1}\mathrm{Mpc})^2$、像素大小为$0.097\\,h^{-1}\mathrm{Mpc}$的投影暗物质场。该像素面积对应于质量约为$10^{10.6}\\,h^{-1}\\,M_\odot$的暗物质晕的特征投影面积。该图揭示了多尺度的投影宇宙网，包括星系团尺度的过密区、纤维状结构和空洞。投影孔径质量与SDSS星系群目录质量在统计上一致，而导出的暗物质晕质量函数大致与模拟目录的预期相符。重建的投影势将Coma星系团置于最深的势阱之一，并靠近推断的投影加速度场的汇聚区域，这表明重建同时保留了局域过密区和连贯的大尺度投影引力结构。这项工作表明，基于扩散的暗物质重建可以应用于真实的星系巡天，从而在SDSS和未来的广域巡天中实现基于暗物质晕质量和空间分辨的暗物质环境的星系演化研究。
英文摘要
Dark matter sets the gravitational environment in which galaxies form and evolve, but cannot be observed directly. We present a conditional diffusion model that reconstructs the projected dark matter density field from the galaxy stellar-mass density field for direct application to galaxy surveys. The model is trained on CAMELS and validated on the independent IllustrisTNG300-1 simulation. Halo masses inferred from the reconstructed projected-aperture measurements agree well with the corresponding true values, with a scatter below 0.2 dex. On 100 kpc scales, reconstructed surface densities show a typical scatter of ~0.3 dex in the regime most relevant for observations. We apply the model to SDSS galaxies with $M_\star\ge10^9\,M_\odot$ in a contiguous low-redshift region. Averaging over 100 stochastic realizations, we reconstruct and publicly release a projected dark matter field covering $90\times90\,(h^{-1}\mathrm{Mpc})^2$ with a pixel size of $0.097\,h^{-1}\mathrm{Mpc}$. This pixel area corresponds to the characteristic projected area of halos with masses of ~$10^{10.6}\,h^{-1}\,M_\odot$. The map reveals the multiscale projected cosmic web, including cluster-scale overdensities, filaments and voids. Projected-aperture masses are statistically consistent with SDSS group-catalog masses, while the derived halo mass function broadly matches mock-catalog expectations. The reconstructed projected potential places Coma in one of the deepest wells and near a convergence region of the inferred projected acceleration field, suggesting that the reconstruction retains both local overdensities and coherent large-scale projected gravitational structure. This work shows that diffusion-based dark matter reconstruction can be applied to real galaxy surveys, enabling halo-mass- and spatially resolved dark-matter-environment-based studies of galaxy evolution in SDSS and future wide-area surveys.
Comments17 pages, 7 figures, Accepted for publication in the ApJL; This is the sixteenth paper in the "From Haloes to Galaxies" series
