Astronomy Department, University of California, Los Angeles, California 90024.
Proc Natl Acad Sci U S A. 1983 Mar;80(6):1764-6. doi: 10.1073/pnas.80.6.1764.
The relatively high-excitation nebula (Westerlund-Smith object 25) in the large Magellanic cloud shows prominent forbidden lines of [Ar IV], the close [Ne IV] pair lambda4724, 4726, [Ca V] lambda5309, [Fe V] lambda4227, and probably [Fe VI] and [Fe VII], as well. A conventional interpretation of observations secured with a vidicon detector at the Cerro Tololo 4-m telescopes indicates an essentially "normal" helium abundance but depletions of N, O, Ne, and other elements with respect to our own galaxy. When a comparison is made with diffuse nebulae or H II regions in the large Magellanic cloud, we find helium to be more abundant, oxygen to be depleted, and nitrogen, neon, and argon to be comparable. The abundance of sulfur is uncertain. Iron in the gaseous phase is certainly more plentiful than in conventional planetaries.
大麦哲伦云里的相对高激发星云(Westerlund-Smith 天体 25)显示出显著的禁线[Ar IV],以及紧密的[Ne IV]对 λ4724、4726、[Ca V] λ5309、[Fe V] λ4227,可能还有[Fe VI]和[Fe VII]。利用 Cerro Tololo 4 米望远镜上的 vidicon 探测器获得的观测结果的传统解释表明,氦的丰度基本“正常”,但相对于我们自己的星系,氮、氧、氖和其他元素都有亏损。当与大麦哲伦云的弥散星云或 H II 区进行比较时,我们发现氦更丰富,氧亏损,氮、氖和氩相当。硫的丰度不确定。气态铁的丰度肯定比传统行星盘中的要丰富。