Observational study of the relation between the AGB evolution and the space distribution of AGB stars

AGB演化与AGB恒星空间分布关系的观测研究

• 批准号: 08640338
• 负责人: NOGUCHI Kunio
• 金额: $ 1.41万
• 依托单位: National Astronomical Observatory
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for Scientific Research (C)
• 财政年份: 1996
• 资助国家: 日本
• 起止时间: 1996 至 1997
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-08640338/
• 关键词: Evolution of AGB stars; Carbon stars; M-type stars; Distribution of AGB stars

We have investigated the evolution of asymptotic giant branch (AGB) stars on the basis of the space distribution of AGB stars. There are two kinds of AGB stars : Carbon stars and M-type stars. We suspect that the space distributions of these two-types of stars are different from each other and that the evolutionary sequence of AGB stars is not the same in the whole Galaxy. To clarify the difference or the similarity of the evolutionary sequence depending on the location in the Galaxy, it is essential to know the space distribution of carbon stars and M-type stars. To get the space distribution of carbon stars we carried out near-infrared photometric observations and estimated total radiant energies (TRE) from individual carbon stars. By comparing the TRE with assumed intrinsic luminosity, distances of carbon stars are evaluated and then we obtained the space distribution of carbon stars. The space distribution of M-type stars is obtained by analyzing the photometric data of IRAS observations. Comparing the space distributions of carbon stars and M-type stars, we have found that two distributions are different from each other. This result shows that the evolutionary sequence of AGB stars is not the same in the whole galaxy.

我们已经根据AGB恒星的空间分布研究了渐近巨型分支（AGB）恒星的演变。有两种AGB星星：碳星和M型星。我们怀疑这两种恒星的空间分布彼此不同，并且在整个银河系中，AGB恒星的进化序列并不相同。为了阐明进化序列的差异或相似性，取决于银河系中的位置，必须了解碳恒星和M型恒星的空间分布。为了获得碳星的空间分布，我们进行了近红外光度观测，并从单个碳恒星中估计了总辐射能（TRE）。通过将TRE与假定的内在光度进行比较，评估了碳恒星的距离，然后我们获得了碳恒星的空间分布。通过分析IRAS观测值的光度数据获得M型恒星的空间分布。比较碳星和M型星的空间分布，我们发现两个分布彼此不同。该结果表明，在整个星系中，AGB恒星的进化序列不相同。