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首页> 外文期刊>Astronomy and astrophysics >Faint recombination lines in Galactic PNe with a [WC] nucleus
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Faint recombination lines in Galactic PNe with a [WC] nucleus

机译：银河系PNe中带有[WC]核的微弱重组线

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Aims. We present spatially resolved high-resolution spectrophotometric data for the planetary nebulae PB8, NGC2867, and PB6. We have analyzed two knots in NGC2867 and PB6 and one in PB8. The three nebulae are ionized by [WC] type nuclei: early [WO] for PB6 and NGC2867 and [WC5-6] in the case of PB8. Our aim is to study the behavior of the abundance discrepancy problem (ADF) in this type of planetary nebula. Methods. We measured a large number of optical recombination (ORL) and collisionally excited lines (CEL), from different ionization stages (many more than in any previous work), thus, we were able to derive physical conditions from many different diagnostic procedures. We determined ionic abundances from the available collisionally excited and recombination lines. Based on both sets of ionic abundances, we derived total chemical abundances in the nebulae using suitable ionization correction factors. Results. From CELs, we have found abundances typical of Galactic disk planetary nebulae. Moderate ADF(O++) were found for PB8 (2.57) and NGC2867 (1.63). For NGC2867, abundances from ORLs are higher but still consistent with Galactic disk planetary nebulae. On the contrary, PB8 presents a very high O/H ratio from ORLs. A high C/O was obtained from ORLs for NGC2867; this ratio is similar to C/O obtained from CELs and with the chemical composition of the wind of the central star, indicating that there was no further C-enrichment in the star, relative to O, after the nebular material ejection. On the contrary, we found in PB8. Interestingly, we obtain (C/O)/(C/O)in PB8 and NGC2867; this added to the similarity between the heliocentric velocities measured in [O III] and O II lines for our three objects argue against the presence of H-deficient metal-rich knots coming from a late thermal pulse event. Key words: planetary nebulae: general - ISM: abundances - stars: Wolf-Rayet - planetary nebulae: individual: PB6 - planetary nebulae: individual:NGC2867 - planetary nebulae: individual: PB8
机译：目的我们介绍了行星状星云PB8，NGC2867和PB6的空间分辨高分辨率分光光度数据。我们在NGC2867和PB6中分析了两个结，在PB8中分析了一个结。这三个星云被[WC]型原子核电离：PB6和NGC2867的早期[WO]和PB8的[WC5-6]。我们的目的是研究这种行星状星云中丰度差异问题（ADF）的行为。方法。我们测量了来自不同电离阶段的大量光学重组（ORL）和碰撞激发线（CEL）（比以前的工作要多得多），因此，我们能够从许多不同的诊断程序中得出物理条件。我们从可用的碰撞激发和复合线确定了离子丰度。基于两组离子丰度，我们使用合适的电离校正因子得出了星云中的总化学丰度。结果。从CEL中，我们发现了银河系盘状行星状星云的典型丰度。发现PB8（2.57）和NGC2867（1.63）的中度ADF（O ++）。对于NGC2867，来自ORL的丰度较高，但仍与银河系盘行星状星云一致。相反，PB8与ORL相比具有很高的O / H比。从ORL中获得了NGC2867的高C / O。该比率类似于从CEL获得的C / O，并且具有中心恒星风的化学成分，这表明在星云物质喷射之后，相对于O，恒星中没有进一步的C富集。相反，我们在PB8中找到了。有趣的是，我们在PB8和NGC2867中获得了（C / O）/（C / O）。这增加了我们三个物体在[O III]和O II线中测得的日心中心速度之间的相似性，这证明了由于晚热脉冲事件而导致的H缺乏金属富集结的存在。关键词：行星状星云：一般-ISM：丰度-恒星：Wolf-Rayet-行星状星云：单个：PB6-行星状星云：单个：NGC2867-行星状星云：单个：PB8

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