Carbonaceous molecules in the oxygen-rich circumstellar environment of binary post-AGB stars: ⋆
Carbonaceous molecules in the oxygen-rich circumstellar environment of binary post-AGB stars: ⋆
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双星 AGB 后富氧星周环境中的碳质分子：⋆
DOI：
10.1051/0004-6361/201117961
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发表时间：
2011
影响因子：
6.5
通讯作者：
Michiel Min
中科院分区：
文献类型：
--
作者：
C. Gielen;C. Gielen;J. Cami;J. Cami;J. Bouwman;Els Peeters;Els Peeters;Michiel Min
上下文。演化恒星的星周环境通常富含分子气体和尘埃。通常情况下，整个环境要么富氧，要么富碳，这取决于中央恒星的演化。目标。在这篇文章中，我们讨论了三个演化的圆盘源，它们的红外光谱中有非典型发射线的证据。这些恒星来自后AGB双星的更大样本，我们有斯皮策红外光谱，其特征是存在稳定的富氧外双星圆盘。我们以前的研究表明，AGB后盘源的红外光谱主要是硅酸盐尘埃发射，通常具有极高的结晶度分数。然而，这里描述的三个来源之所以被选中，是因为它们显示了一种特殊的分子化学。方法：研究方法。利用斯皮策红外光谱，我们详细研究了这三颗样品恒星的特殊矿物学。利用观测到的发射特征，我们识别了不同的观测到的尘埃、分子和气体物种。结果。红外光谱显示了各种富氧尘埃成分以及二氧化碳气体的发射特征。所有这三个来源都显示出通常归因于多环芳烃的强红外波段。此外，两个样本源显示C60富勒烯谱带。结论。尽管大多数后AGB盘源在其星周环境中以硅酸盐尘埃为主，但我们确实发现了证据，至少对某些源来说，必须进行额外的处理才能解释大的碳质分子的存在。有证据表明，其中一些来源仍然富含氧气，这使得检测到这些分子更加令人惊讶。
Context. The circumstellar environment of evolved stars is generally rich in molecular gas and dust. Typically, the entire environment is either oxygen-rich or carbon-rich, depending on the evolution of the central star. Aims. In this paper we discuss three evolved disc sources with evidence of atypical emission lines in their infrared spectra. The stars were taken from a larger sample of post-AGB binaries for which we have Spitzer infrared spectra, characterised by the presence of a stable oxygen-rich circumbinary disc. Our previous studies have shown that the infrared spectra of post-AGB disc sources are dominated by silicate dust emission, often with an extremely high crystallinity fraction. However, the three sources described here are selected because they show a peculiar molecular chemistry. Methods. Using Spitzer infrared spectroscopy, we study in detail the peculiar mineralogy of the three sample stars. Using the observed emission features, we identify the different observed dust, molecular and gas species. Results. The infrared spectra show emission features due to various oxygen-rich dust components, as well as CO2 gas. All three sources show the strong infrared bands generally ascribed to polycyclic aromatic hydrocarbons. Furthermore, two sample sources show C60 fullerene bands. Conclusions. Even though the majority of post-AGB disc sources are dominated by silicate dust in their circumstellar environment, we do find evidence that, for some sources at least, additional processing must occur to explain the presence of large carbonaceous molecules. There is evidence that some of these sources are still oxygen-rich, which makes the detection of these molecules even more surprising.
黄长石晶体的红外吸收光谱
DOI：
--
发表时间：
2003
期刊：
Grain Formation Workshop XXIII
影响因子：
--
作者：
C.Koike;K.Koike;H.Sogawa;H.Sogawa;Yuki Kimura;Yuki Kimura;Mami Kurumada;T.Naoi;M.Matsuura;C.Koike;C.Koike;H.Chihara;H.Suto;C.Koike;H.Chihara
通讯作者：
H.Chihara