发表机构
Perimeter Institute for Theoretical Physics; Institute for Advanced Study; University of Exeter（Perimeter理论物理研究所; 普林斯顿高等研究院; 埃克塞特大学）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
本文利用扩散模型先验，量化了光学强度干涉测量中无相位数据可恢复的信息，并证明下一代干涉仪的信噪比足以成像复杂恒星表面。
AI 中文摘要
光学强度干涉测量（II）原则上可以分辨角尺度为 $\theta\sim \lambda/B$ 的结构，但它仅测量可见度的平方 $|{\cal V}|^2$，丢弃了傅里叶相位。我们利用基于评分的扩散模型作为非参数图像先验，量化了在总信噪比和阵列配置条件下，从无相位的 $|{\cal V}|^2$ 测量中实际能恢复哪些信息。我们构建了一个图像重建流程，并通过重建多种图像（包括黑洞吸积盘的GRMHD模拟以及太阳的SDO/HMI连续谱图像）从无相位傅里叶振幅中验证了该流程。利用模拟数据，我们绘制了类太阳恒星表面的重建保真度随噪声水平、$(u,v)$ 采样点数和最大基线 $B_{\rm max}$ 的变化图，表面图覆盖了不同活动水平。我们发现，只要 $(u,v)$ 平面采样足够密集，保真度仅通过所关注表面特征的总信噪比（SNR）依赖于数据。这些结果表明，下一代强度干涉仪观测真实源所达到的信噪比水平足以对高度复杂的恒星表面进行成像。
英文摘要
Optical intensity interferometry (II) can in principle resolve structure on angular scales $θ\sim λ/B$, but it measures only the squared visibility $|{\cal V}|^2$, discarding Fourier phase. We quantify what information can actually be recovered from phase-less $|{\cal V}|^2$ measurements as a function of the aggregate signal-to-noise ratio and array configuration, using score-based diffusion models as non-parametric image priors. We construct an image reconstruction pipeline, and validate it by reconstructing a variety of images, including GRMHD simulations of black hole accretion disks and actual SDO/HMI continuum images of the Sun, from phase-less Fourier amplitudes. Using simulated data, we map the reconstruction fidelity of Sun-like stellar surfaces as a function of noise level, number of $(u,v)$ samples, and maximum baseline $B_{\rm max}$, for surface maps spanning a range of activity levels. We find that fidelity depends on the data only through the total signal to noise ratio (SNR) of the surface features of interest, provided that the $(u,v)$ plane is sampled sufficiently densely. These results show that the SNR levels achieved by next-generation intensity interferometers observing realistic sources are sufficient to image highly complicated stellar surfaces.
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