论文标题
紧凑的银河行星星云中的碳丰富度：一项紫外光谱研究，其空间望远镜成像光谱仪（STIS）
Carbon Abundances in Compact Galactic Planetary Nebulae: An Ultraviolet spectroscopic study with the Space Telescope Imaging Spectrograph (STIS)
论文作者
论文摘要
我们调查了一个紧凑的银河行星星云（PNE）样品，并在哈勃太空望远镜（HST/STIS）上使用了空间望远镜成像光谱仪，以确定其气相碳的丰度。 PNE中的碳丰度限制了其渐近巨型分支（AGB）祖细胞以及宇宙回收的性质。我们测量了11个紧凑的银河pne的碳丰度或其极限，特别是增加了银河pne的样品，其基于HST紫外线光谱的碳丰度。大多数靶标的灰尘含量已从Spitzer光谱中的其他地方进行了研究。鉴于星云的紧凑性，紫外线和红外光谱都可以直接与研究气体和尘埃碳进行比较。我们发现，耐碳（C/O <1）紧凑的银河pne具有富氧的灰尘类型（ORD），而其碳增强的对应物（C/O> 1）具有富含碳的灰尘（CRD），确认气体和尘埃碳含量之间的相关性，这是大岩质云云pne所知的。基于AGB进化的预期最终产量的模型，我们将本研究的大部分碳pne pne解释为〜1.1-1.2 m $ $ _ {\ odot} $ stars的后代，这些后代在红色巨型分支（RGB）上经历了一些超级混合（RGB），但他们没有经过AGB，但并未穿过碳恒星阶段。该组中的大多数pne具有双极形态，可能是由于存在亚晶状体伴侣。我们的样品中的碳增强pne可能是〜1.5-2.5 m $ _ {\ odot} $范围的恒星的后代，具体取决于它们的原始金属性。
We surveyed a sample of compact Galactic planetary nebulae (PNe) with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST/STIS) to determine their gas-phase carbon abundances. Carbon abundances in PNe constrain the nature of their asymptotic giant branch (AGB) progenitors, as well as cosmic recycling. We measured carbon abundances, or limits thereof, of 11 compact Galactic PNe, notably increasing the sample of Galactic PNe whose carbon abundance based on HST ultraviolet spectra is available. Dust content of most targets has been studied elsewhere from Spitzer spectroscopy; given the compact nature of the nebulae, both UV and IR spectra can be directly compared to study gas- and dust-phase carbon. We found that carbon-poor (C/O<1) compact Galactic PNe have oxygen-rich dust type (ORD), while their carbon-enhanced counterparts (C/O>1) have carbon-rich dust (CRD), confirming the correlation between gas- and dust-phase carbon content which was known for Magellanic Cloud PNe. Based on models of expected final yields from AGB evolution we interpret the majority of the carbon-poor PNe in this study as the progeny of ~1.1-1.2 M$_{\odot}$ stars that experienced some extra-mixing on the red giant branch (RGB), they went through the AGB but did not go through the carbon star phase. Most PNe in this group have bipolar morphology, possibly due to the presence of a sub-solar companion. Carbon-enhanced PNe in our sample could be the progeny of stars in the ~1.5-2.5 M$_{\odot}$ range, depending on their original metallicity.
