尺度向量对齐：一种面向天文图像空间分辨形态相似性的尺度感知框架
Scale-Vector Alignment: A Scale-Aware Framework for Spatially Resolved Morphological Similarity in Astronomical Images
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中文总结 AI 辅助
提出尺度向量对齐方法，基于约束扩散分解比较天文图像中不同示踪剂的多尺度形态相似性，在多个天体上验证了其有效性。
中文摘要 AI 辅助
使用不同示踪剂绘制的天文图不期望具有相同的形态。激发、光学深度、化学、辐射和星际介质相态会改变示踪剂的响应，由此产生的差异可能同时依赖于位置和空间尺度。我们提出了尺度向量对齐，一种基于约束扩散分解（CDD）的尺度感知方法。CDD将图像分解为局部尺度分量；在每个位置，它们的振幅定义一个尺度向量，描述测量强度在空间尺度上的分布。我们将像素级相似度$\Spix(x,y)$定义为两个局部尺度向量的归一化对齐。归一化去除了整体振幅，因此$\Spix$比较的是相对尺度组成而非绝对通量。我们还通过比较每个空间尺度上的两个CDD分量图来定义尺度级相似度$\Sscale(l)$。使用空间位移构建$\Spix$的经验移位参考分布。在猎户座A中，与尘埃导出的柱密度图相似度最高的示踪剂随柱密度增加从$^{12}$CO变为$^{13}$CO再变为C$^{18}$O。在NGC~6334I(N)中，线-连续谱相似度在最亮的致密结构周围局部降低，那里辐射转移效应可以改变观测到的线形态。在NGC~3627中，CO与21~$\mu$m发射最相似，且$\Sscale$在中间亚千秒差距尺度达到最大值。该方法测量两个示踪剂在何处具有相似的多尺度结构以及它们的空间分布在哪些尺度上一致。实现代码公开于此https URL。
英文摘要
Astronomical maps made with different tracers are not expected to have identical morphology. Excitation, optical depth, chemistry, radiation, and ISM phase alter the response of a tracer, and the resulting differences can depend on both position and spatial scale. We propose scale-vector alignment, a scale-aware method based on Constrained Diffusion Decomposition (CDD). CDD decomposes an image into localized scale components; at each position, their amplitudes define a scale vector that describes how the measured intensity is distributed over spatial scale. We define the pixel-wise similarity $\Spix(x,y)$ as the normalized alignment of two local scale vectors. The normalization removes the overall amplitude, so $\Spix$ compares relative scale composition rather than absolute flux. We also define the scale-wise similarity $\Sscale(l)$ by comparing the two CDD component maps at each spatial scale. Spatial shifts are used to construct an empirical shifted reference distribution for $\Spix$. In Orion~A, the tracer with the highest similarity to the dust-derived column-density map changes from $^{12}$CO to $^{13}$CO to C$^{18}$O toward higher column density. In NGC~6334I(N), the line--continuum similarity decreases locally around the brightest compact structures, where radiative-transfer effects can alter the observed line morphology. In NGC~3627, CO is most similar to 21~$μ$m emission, and $\Sscale$ reaches its maximum at an intermediate sub-kpc scale. The method measures where two tracers have similar multiscale structure and at which scales their spatial distributions agree. The implementation is publicly available at https://github.com/meng-ke/Scale-Vector-Alignment.
发表机构
- Nanjing University（南京大学）
- Yunnan University（云南大学）
机构由 AI 辅助整理，请以论文原文为准。
