Dust grains and gas in the circumstellar envelopes around luminous red giant stars
Dust grains and gas in the circumstellar envelopes around luminous red giant stars
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DOI：
10.1086/164776
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发表时间：
1986-12
期刊：
影响因子：
--
通讯作者：
B. Zuckerman;H. M. Dyck
中科院分区：
文献类型：
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作者：
B. Zuckerman;H. M. Dyck
在IRAS点源星表中，已经为100多颗最亮的演化恒星绘制了远红外色-色图。这些图用于推断12至100微米之间的尘埃颗粒发射率指数（p）的平均值。富碳和富氧环境中的颗粒在12至25微米和60至100微米之间的p值相似，但在25至60微米之间，富氧恒星的p值大约大0.4。S型恒星周围的尘埃颗粒似乎有25到60微米的发射率，更接近于富O环境中的颗粒，而不是富C环境中的颗粒。来自不同恒星的CO和HCN排放被用来将一些恒星重新分类为富氧或富碳。
Far-infrared color-color diagrams have been constructed for over 100 of the brightest evolved stars in the IRAS Point Source Catalog. The diagrams are used to deduce average values of the dust grain emissivity index (p) between 12 and 100 microns. Grains in C-rich and O-rich environments have similar values of p between 12 and 25 microns and between 60 and 100 microns, but between 25 and 60 microns p is larger by approximately 0.4 for the O-rich stars. Dust grains in envelopes around S-type stars seem to have 25 to 60 micron emissivities more nearly like grains in O-rich rather than C-rich environments. CO and HCN emissions from various stars are used to reclassify several stars as oxygen or carbon rich.