The geometric structure of supernova remnants (SNR) provides a clue to unveiling the pre-explosion evolution of their progenitors. Here we present an X-ray study of N103B (0509–68.7), a Type Ia SNR in the Large Magellanic Cloud, that is known to be interacting with dense circumstellar matter (CSM). Applying our novel method for feature extraction to deep Chandra observations, we have successfully resolved the CSM, Fe-rich ejecta, and intermediate-mass element (IME) ejecta components, and revealed each of their spatial distributions. Remarkably, the IME ejecta component exhibits a double-ring structure, implying that the SNR expands into an hourglass-shape cavity and thus forms bipolar bubbles of the ejecta. This interpretation is supported by more quantitative spectroscopy that reveals a clear bimodality in the distribution of the ionization state of the IME ejecta. These observational results can be naturally explained if the progenitor binary system had formed a dense CSM torus on the orbital plane prior to the explosion, providing further evidence that the SNR N103B originates from a single-degenerate progenitor.

超新星遗迹 (SNR) 的几何结构为揭示其祖先在爆炸前的演化提供了线索。在这里，我们展示了 N103B (0509-68.7) 的 X 射线研究，这是大麦哲伦星云中的 Ia 型 SNR，已知与致密星周物质 (CSM) 相互作用。将我们的特征提取新方法应用于深部钱德拉观测，我们成功解析了 CSM、富铁喷射物和中等质量元素 (IME) 喷射物成分，并揭示了它们的每个空间分布。值得注意的是，IME喷射物成分呈现出双环结构，这意味着SNR扩展为沙漏形腔，从而形成喷射物的双极气泡。这种解释得到了更多定量光谱的支持，这些光谱揭示了 IME 喷射物电离状态分布的明显双峰性。如果前身双星系统在爆炸前在轨道平面上形成了一个致密的 CSM 环面，这些观测结果可以自然地得到解释，这进一步证明了 SNR N103B 起源于一个单简并前身。