arXiv:2510.14102astro-ph.IMcs.AI2025-10中稿 · A&A被引 3

用深度学习压缩X光谱数据,提取物理有意义的低维表示。

Extracting latent representations from X-ray spectra. Classification, regression, and accretion signatures of Chandra sources

  • 用基于Transformer的自编码器将光谱压缩到8维潜在空间。
  • 对8类源分类准确率达40%,仅限活动星系核与致密天体时升至69%。
  • 潜变量与光谱和时序特性相关,适合大样本巡天分类与回归任务。

在大规模X射线巡天时代,光谱特征至关重要。尽管机器学习方法已被证明有效,但尚未广泛应用于如钱德拉源目录(Chandra Source Catalog, CSC)这类大型光谱数据集。本文提出一种基于Transformer的自编码器,将钱德拉X射线光谱压缩为8维潜在表示,以获得紧凑且具物理意义的表征。通过分类、回归与可解释性分析验证该表示的有效性,并测量光谱与时间域属性间的互信息,助力未来暂现事件识别。利用外部星表中的天体类型和物理统计量作为标签,评估了重建精度、8类天体的聚类性能,以及与硬度比、氢柱密度($N_H$)等物理量的相关性。重建后,潜在空间中分类准确率约为40%,若仅限于活动星系核与恒星级致密天体,则提升至约69%。潜变量与光谱及时间特性显著相关,表明其捕捉了物理相关信息。直接从光谱学习的特征在表现上可媲美需额外计算的人工特征,适用于大规模巡天的分类与回归,且与时间域属性共享互信息。该方法可适配现有及未来X射线星表。

原文摘要 · Abstract (English)

Spectral signatures are crucial in the era of large X-ray surveys. Automatic machine learning methods have proven useful in this respect, but so far they have not been applied to large spectral datasets, such as the Chandra Source Catalog (CSC). This work aims to develop a compact and physically meaningful representation of Chandra X-ray spectra using deep learning. To verify that the learned representation captures relevant information, we evaluate it through classification, regression, and interpretability analyses, and measure the mutual information between spectral and time-domain properties of these sources, aiding in the future identification of transient events. We use a transformer-based autoencoder to compress X-ray spectra into representations in an 8-dimensional latent space. Astrophysical source types and physical summary statistics are compiled from external catalogs. We evaluate the learned representation in terms of spectral reconstruction accuracy, clustering performance on 8 known astrophysical source classes, and correlation with physical quantities such as hardness ratios and hydrogen column densities ($N_H$). Upon reconstruction, clustering in the latent space yields a balanced classification accuracy of $\sim$40% across the 8 source classes, increasing to $\sim$69% when restricted to AGNs and stellar-mass compact objects exclusively. Moreover, latent features correlate with spectral and temporal properties, suggesting that the compressed representation captures physically relevant information. Features learned directly from X-ray spectra capture relevant physical information as effectively as human-extracted features that require additional computations. They can be used for both classification and regression in large surveys, and also share mutual information with time-domain properties. The method can be adapted to existing and upcoming X-ray catalogs.

X射线光谱深度学习天体分类潜在表示

Thank you to arXiv for use of its open access interoperability. PaperDance 不是 arXiv 官方产品;中文卡片由大模型生成,请以原文为准。