AI 中文总结
本研究针对超新星抛射物与星周介质相互作用的问题，提出结合射电与X射线信号的策略，可通过射电光变曲线特征及X射线信号约束星周介质结构，经SN 1993j和SN 2023ixf验证，非对称星周介质与观测吻合。
AI 中文摘要
超新星（SN）抛射物与致密星周介质（CSM）的相互作用会将激波动能转化为多波段辐射。我们研究X射线与射电辐射对CSM几何结构的依赖，考虑CSM的球形、沙漏形和盘形三种形态。我们发现，对于球形与非球形CSM结构，X射线和射电的谱特性及光变曲线特性存在显著差异：对于非球形CSM，由于未受激CSM的有效自由-自由吸收，射电光变曲线在峰值频率附近趋于平缓；当观测者视线方向的CSM密度大于其他方向时，射电光变曲线的早期上升段更平缓；若观测者视线方向的CSM密度较低，射电光变曲线在峰值附近趋于平缓，且X射线中的反向激波分量可忽略。基于这些特征，我们提出一种方法，可通过射电光变曲线峰值附近的上升段约束CSM结构，同时表明射电光变曲线峰值后的衰减段可提供CSM密度剖面是否类似星风的信息；我们进一步利用X射线信号验证从射电提取的信息。我们将该策略应用于SN 1993j和SN 2023ixf，发现两个超新星的非对称CSM与射电、X射线观测结果高度吻合，且是文献中提出的非星风场景的可行替代方案。我们的研究结果凸显了射电与X射线信号对超新星前身星质量损失历史的关键揭示作用。
英文摘要
The interaction of supernova (SN) ejecta with the dense circumstellar medium (CSM) converts shock kinetic energy into radiation across multiple wavebands. We investigate the dependence of the X-ray and radio emission on the CSM geometry, considering spherical, hourglass, and disk shapes for the CSM. We find that the spectral and light-curve properties, both in X-ray and radio, significantly differ for spherical and non-spherical CSM structures. For a non-spherical CSM, the radio light curve flattens out near the peak frequency, due to efficient free-free absorption by the unshocked CSM. Moreover, the early rise of the radio light curve is shallower when the CSM density along the observer line of sight is larger than that in other directions. If the CSM density is lower along the observer line of sight, the radio light curve flattens near its peak, and the reverse-shock component is negligible in X-rays. Building on these features, we provide a method to constrain the CSM structure based on the rising part the radio light curve in the proximity of its peak; we show that the decay part of the radio light curve, after its peak, carries insight on whether the CSM density profile is wind-like or not. We further adopt the X-ray signal to corroborate the information extracted from radio. We test our strategy on SN 1993j and SN 2023ixf. For both SNe, we find that an asymmetric CSM is in excellent agreement with radio and X-ray observations and provides a viable alternative to non-wind scenarios suggested in the literature. Our findings highlight the crucial insight provided by radio and X-ray signals into the mass-loss history of the SN progenitor.
Comments21 pages, 11 figures, comments welcome
