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arXiv 0906.4820astro-ph.SR
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Spitzer 24 um行星状星云图像

Spitzer 24 um Images of Planetary Nebulae

Y. -H. Chu, R. A. Gruendl, M. A. Guerrero, K. Y. L. Su, J. Bilikova, M. Cohen, Q. A. Parker, K. Volk, A. Caulet, W. -P. Chen, J. L. Hora, T. Rauch

摘要:

Spitzer MIPS 24 μ m图像获得了36个银河系行星状星云(PNe)的图像,这些星云的中心恒星是有效温度为~ 100,000 K或更高的热白矮星(WD)或前WD。在这些PNe中的28个中检测到漫射24 μ m发射。八个未检测到的是角度大的PNe,具有非常低的H-α表面亮度。我们发现这些PNe的24 μ m发射和H-α线发射之间有三种类型的对应关系:6个显示24 μ m发射比H-α发射更扩展,9个在24 μ m和H-α处具有类似的程度,13个显示H-α壳中心附近的扩散24 μ m发射。这三组PNe的大小和表面亮度以及未检测到的情况表明了一个进化序列,最年轻的PNe最亮,而最进化的PNe未被检测到。这些PNe的24 μ m谱带发射是由[O IV] 25.9 μ m和[Ne V] 24.3 μ m谱线发射以及尘埃连续谱发射组成的,但这三个分量的相对贡献取决于中心恒星的温度以及星云中气体和尘埃的分布。

英文摘要:

Spitzer MIPS 24 um images were obtained for 36 Galactic planetary nebulae (PNe) whose central stars are hot white dwarfs (WDs) or pre-WDs with effective temperatures of ~100,000 K or higher. Diffuse 24 um emission is detected in 28 of these PNe. The eight non-detections are angularly large PNe with very low H-alpha surface brightnesses. We find three types of correspondence between the 24 um emission and H-alpha line emission of these PNe: six show 24 um emission more extended than H-alpha emission, nine have a similar extent at 24 um and H-alpha, and 13 show diffuse 24 um emission near the center of the H-alpha shell. The sizes and surface brightnesses of these three groups of PNe and the non-detections suggest an evolutionary sequence, with the youngest ones being brightest and the most evolved ones undetected. The 24 um band emission from these PNe is attributed to [O IV] 25.9 um and [Ne V] 24.3 um line emission and dust continuum emission, but the relative contributions of these three components depend on the temperature of the central star and the distribution of gas and dust in the nebula.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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