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arXiv 0708.4246astro-ph
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过渡天体的射电和红外观测

Radio and Infrared observations of Transition Objects

L. Cerrigone, J. L. Hora, G. Umana, C. Trigilio

摘要:

观测从准行星状星云(PN)过渡到年轻行星状星云(PN)的天体,当中央恒星辐射开始激发包层时,可以帮助我们了解星周喷出物的演化及其形成机制。在我们的项目中,我们选择了一个热的后AGB恒星作为过渡阶段的候选者。无线电观测已经导致在大约一半的目标中检测到来自电离壳层的自由-自由辐射,为我们提供了电离和非电离过渡物体的两个子样本。我们现在正在斯皮策太空望远镜上使用IRAC和IRS来确定是否存在扩展发射(IRAC)并研究我们的目标化学(IRS)。特别是,通过比较两个子样本的光谱,IRS的观测将使我们能够检查电离锋的存在如何影响星周包络。IRAC的测量,结合以前的文献中,将给我们的信息的范围和物理条件的尘埃成分。

英文摘要:

Observing objects in transition from pre- to young Planetary Nebula (PN), when the central star radiation starts to excite the envelope, can help us to understand the evolution of the circumstellar ejecta and their shaping mechanism/s. In our project we have selected a sample of hot post-AGB stars as Transition Phase candidates. Radio observations have led to detect free-free radiation from an ionized shell in about half of our targets, providing us with two sub-samples of ionized and non ionized Transition Objects. We are now using IRAC and IRS on the Spitzer Space Telescope to determine if extended emission is present (IRAC) and to study our targets' chemistry (IRS). In particular, by comparing spectra from the two sub-samples, the IRS observations will enable us to check how the presence of an ionization front effects the circumstellar envelope. The IRAC measurements, combined with previous ones in the literature, will give us information on the extent and physical conditions of the dust components.

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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