光子级别的X射线与γ射线联合分析：应用于MSH 15-52
Joint X-ray and gamma-ray analysis at the photon level: Application to MSH 15-52
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中文总结 AI 辅助
本研究将eROSITA X射线数据导入Gammapy框架，提出3D X射线与γ射线事件级联合分析流程，验证了其可行性，为PWNe等天体的多波段联合分析提供了新途径。
中文摘要 AI 辅助
对光子事件级别的多波长（MWL）数据进行联合分析颇具挑战性，但相较于拟合导出的流量点，它提供了一种统计上更优的数据拟合方法。X射线与γ射线仪器的数据因具有共同的物理起源（相同的粒子群与非热过程），且格式高度相似，非常适合联合描述。这种描述对脉冲星风星云（PWNe）这类天体尤为必要，PWNe是源自脉冲星加速粒子外流的弥散源，光子发射由粒子与周围磁场及辐射场相互作用产生，其丰富的MWL辐射使MWL研究对全面获取PWNe物理性质至关重要。我们通过将eROSITA X射线数据导入Gammapy软件框架，展示了光子事件级别的3D X射线与γ射线MWL联合分析。我们提出了将eROSITA 3D（两个空间维度、一个光谱维度）事件数据转换为Gammapy可读格式的流程，通过与标准X射线数据产品及分析对比验证了该方法。此外，我们还开展了eROSITA 3D数据分析，以及与3D H.E.S.S.数据、Fermi 4FGL星表流量点的联合拟合。通过对PWN MSH 15-52数据的分析，我们表明Gammapy提取的eROSITA光谱的1D拟合结果与原生X射线工具PyXspec的结果一致；我们证实X射线数据可开展含背景扣除和背景建模的3D分析，且Gammapy可实现3D X射线与γ射线数据的事件级联合分析，这为PWNe及其他天体的联合分析开辟了新的可能性。
英文摘要
Joint analysis of multi-wavelength (MWL) data at the level of photon events is challenging, but it provides a statistically preferable method of fitting the data, in contrast to fitting derived flux points. Data from X-ray and gamma-ray instruments are well-suited for a joint description, due to their common physical origin (same particle population and non-thermal processes) and incidentally also due to the high similarity of their formats. Such a description is especially desirable for objects such as pulsar wind nebulae (PWNe), diffuse sources that originate from outflows of particles that have been accelerated by pulsars. Photon emission is generated by particle interactions with the surrounding magnetic and radiation fields. The rich MWL emission from PWNe renders MWL studies essential to obtain a comprehensive picture of their physical properties. We demonstrate a joint MWL analysis of 3D X-ray and gamma-ray data at the photon event level by importing eROSITA X-ray data into the Gammapy software framework. We present our pipeline for converting eROSITA 3D (two spatial and one spectral dimension) event data into a Gammapy-readable format. We validated the approach through comparison with standard X-ray data products and analysis. Furthermore a 3D eROSITA data analysis as well as a joint fit with 3D H.E.S.S. data and Fermi 4FGL catalogue flux points was performed. We show through the analysis of data from the PWN MSH\,15-52 that 1D fits of Gammapy-extracted eROSITA spectra agree with the results of the native X-ray tool PyXspec. We demonstrate that 3D analyses on X-ray data can be conducted, with both background subtraction and background modelling. Furthermore, we show that joint analyses at event level between 3D X-ray and gamma-ray data can be conducted in Gammapy. This opens up exciting new possibilities for joint analyses of PWNe and other objects.
