论文标题
在银河系热媒介中广泛检测两个成分
Widespread Detection of Two Components in the Hot Circumgalactic Medium of the Milky Way
论文作者
论文摘要
银河系（MW）周围是环境层培养基（CGM），这是一种延伸的热气体储层，对MW的演变具有重要意义。我们使用Halosat All-Sky调查来研究CGM的软X射线发射，以更好地定义其分布和结构。我们将先前对南部CGM（银河纬度B <-30 ver）的Halosat研究扩展到包括北CGM（B> 30 dEG），并找到证据表明，在不同温度下至少需要两个热气模型成分来产生观察到的发射。冷却器组件的典型温度为kt〜0.18 keV，而较热的组件的典型温度为kt〜0.7 keV。温暖和热组件中的发射度量的范围很大（〜0.005-0.03，〜0.0005-0.004 cm -6 PC），表明CGM是块状的。在北部发现了一块相对一致的CGM，可以使用堆叠频谱对CGM频谱进行更细节的研究。堆叠频谱的描述很好地描述了一个模型，其中包括Kt = 0.166 +/- 0.005 keV的两个热气体成分，KT = 0.69 +0.04 -0.05 kev。作为添加热分成分的替代方案，还测试了CGM的霓虹灯增强单温模型，并发现其拟合统计数据较差和残留差。
Surrounding the Milky Way (MW) is the circumgalactic medium (CGM), an extended reservoir of hot gas that has significant implications for the evolution of the MW. We used the HaloSat all-sky survey to study the CGM's soft X-ray emission in order to better define its distribution and structure. We extend a previous HaloSat study of the southern CGM (Galactic latitude b < -30 deg) to include the northern CGM (b > 30 deg) and find evidence that at least two hot gas model components at different temperatures are required to produce the observed emission. The cooler component has a typical temperature of kT ~ 0.18 keV, while the hotter component has a typical temperature of kT ~ 0.7 keV. The emission measure in both the warm and hot components has a wide range (~ 0.005 - 0.03, ~ 0.0005 - 0.004 cm-6 pc respectively), indicating that the CGM is clumpy. A patch of relatively consistent CGM was found in the north, allowing for the CGM spectrum to be studied in finer detail using a stacked spectrum. The stacked spectrum is well described with a model including two hot gas components at temperatures of kT = 0.166 +/- 0.005 keV and kT = 0.69 +0.04 -0.05 keV. As an alternative to adding a hot component, a neon-enhanced single-temperature model of the CGM was also tested and found to have worse fit statistics and poor residuals.
