Far-infrared line observations of planetary nebulae. I - The forbidden O III spectrum
Far-infrared line observations of planetary nebulae. I - The forbidden O III spectrum
复制标题
行星状星云的远红外线观测。
DOI：
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发表时间：
1985
期刊：
影响因子：
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通讯作者：
M. Werner
中科院分区：
文献类型：
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作者：
H. Dinerstein;D. Lester;M. Werner
已对六个行星状星云进行了O III 远红外精细结构线的观测。红外测量与光学 O III 线通量相结合，可探测气体中的物理状况。根据观察到的线强度比，获得了电子温度和密度的同时解决方案，以及评估不均匀性重要性的方法。由远红外 O III 线确定的密度与其他离子的密度诊断一致，表明排放气体中的密度相当均匀。温度分别根据 O III 4363/5007 A 和 5007 A/52 微米强度比确定并进行比较。系统地更高的值是从前一个比率得出的，这预计是从不等温的星云中得出的。考虑到这些星云内存在的温度变化会提高其衍生的氧丰度，其测定值与太阳值相一致。
Observations of the far-infrared fine structure lines of O III have been obtained for six planetary nebulae. The infrared measurements are combined with optical O III line fluxes to probe physical conditions in the gas. From the observed line intensity ratios, a simultaneous solution was obtained for electron temperature and density, as well as means of evaluating the importance of inhomogeneities. Densities determined from the far-infrared O III lines agree well density diagnostics from other ions, indicating a fairly homogeneous density in the emitting gas. Temperatures are determined separately from the O III 4363/5007 A and 5007 A/52 micron intensity ratios and compared. Systematically higher values are derived from the former ratio, which is expected from a nebula which is not isothermal. Allowance for the presence of temperature variations within these nebulae raises their derived oxygen abundances, determinations to be reconciled with the solar value.