论文标题
与超新星残留W28相关的高速星际吸收
High-velocity interstellar absorption associated with the supernova remnant W28
论文作者
论文摘要
我们提供了对CD-23 13777的视线获得的中等高分辨率光谱的分析，该光谱是一种O9超级巨头，探测与超新星残留W28相关的高速速度星际气体。在星际NA I D和CA II H和K线朝CD-23 13777的星际内和Ca II H和K线中都可以看到高阳性和高负速度的吸收成分。高速度成分表现出较低的Na I/Ca II比率，这表明通过冲击溅射会有效地破坏了谷物的有效谷物破坏。对于在较低速度下看到的组件的CH+和高CH+/CH比的高柱密度可能表明与W28相互作用的云中湍流增强。 Na I和Ca II吸收CD-23 13777中最高的正速和负速度表明，与W28相关的爆炸波的速度至少为150 km/s，该值显着高于大多数先前的估计值。 CD-23 13777的视线经过非常接近SNR与分子云之间相互作用的位置，向东北部的相互作用。东北分子云表现出宽阔的分子线发射，众多位置的OH MASER发射以及明亮的GEV和TEV Gamma-ray发射。因此，CD-23 13777的视线是对其周围环境中W28和密集分子气之间相互作用的独特而有价值的探针。紫外线和可见波长的未来观察将有助于更好地限制这种视线沿线震惊和静止气体中的丰度，运动学和物理状况。
We present an analysis of moderately high resolution optical spectra obtained for the sight line to CD-23 13777, an O9 supergiant that probes high velocity interstellar gas associated with the supernova remnant W28. Absorption components at both high positive and high negative velocity are seen in the interstellar Na I D and Ca II H and K lines toward CD-23 13777. The high velocity components exhibit low Na I/Ca II ratios, suggesting efficient grain destruction by shock sputtering. High column densities of CH+, and high CH+/CH ratios, for the components seen at lower velocity may be indicative of enhanced turbulence in the clouds interacting with W28. The highest positive and negative velocities of the components seen in Na I and Ca II absorption toward CD-23 13777 imply that the velocity of the blast wave associated with W28 is at least 150 km/s, a value that is significantly higher than most previous estimates. The line of sight to CD-23 13777 passes very close to a well-known site of interaction between the SNR and a molecular cloud to the northeast. The northeast molecular cloud exhibits broad molecular line emission, OH maser emission from numerous locations, and bright extended GeV and TeV gamma-ray emission. The sight line to CD-23 13777 is thus a unique and valuable probe of the interaction between W28 and dense molecular gas in its environs. Future observations at UV and visible wavelengths will help to better constrain the abundances, kinematics, and physical conditions in the shocked and quiescent gas along this line of sight.
