SiO脉泽星的近红外测光与分析

Near-infrared Photometry and Analysis of SiO Maser Stars of Different Types

本文给出３５个不同类型含ＳｉＯ（ｖ＝１，Ｊ＝１－０）脉泽发射的ＡＧＢ星的近红外观测结果（其中包括６个Ⅰ型ＯＨ星，１３个Ⅱ型ＯＨ星，９个仅有ＳｉＯ脉泽的星以及７个无ＯＨ脉泽但有ＳｉＯ和Ｈ２Ｏ脉泽的星）．得出了它们的ＪＨＫ星等和流量．同时经认证找出了它们对应的ＩＲＡＳ观测数据．通过对它们的近红外、中远红外以及ＯＨ射电资料的同时分析，得出了不同类型ＳｉＯ脉泽星的色指数、谱斜率以及在近红外波段上拟合的等效黑体温度Ｔｅｑ．由红外及ＯＨ射电资料导出了其中心星的质量损失率Ｍ，并在此基础上结合已知的ＳｉＯ脉泽源资料，找出了不同类型ＳｉＯ脉泽星各量之间的关系．计算结果表明，ＳｉＯ脉泽具有普遍性，在各类脉泽星中都可出现．ＳｉＯ脉泽的光度与质量损失率弱相关，并且从（Ｍｉｒａ）ＳｉＯ到（ＯＨ／ＩＲ）ＳｉＯ逐渐增加．ＳｉＯ脉泽的流量与近红外“色”以及等效黑体温度Ｔｅｑ的关系较为密切．ＳｉＯ脉泽积分流量的上限与ＩＲＡＳ在１２μｍ和２５μｍ上流量分别都相关．本文对ＳｉＯ脉泽在ＡＧＢ演化中的地位和特殊性进行了简单讨论．

Near-infrared photometry of 35 SiO maser stars of various types is presented in this paper.6 OH maser stars of type Ⅰ,13 OH maser stars of type Ⅱ,9 pure SiO maser stars,7 SiO,H 2O maser stars are included in it.Combining the JHK flux densities from the IRAS data,the distributions of SiO maser stars of different types on two color-color diagrams are obtained.The spectral slopes,equivalent black body temperature,maser luminosities and mass-loss rates of the central stars are calculated from the infrared and radio data.The parameters are then compared and analysed for the SiO maser stars of various types.The results show that SiO masers are common in AGB stages.Integrated luminosities of SiO masers are only weakly correlated with mass-loss rates,and increase slowly along the sequence from Mira stars to OH/IR stars.The flux densities of the SiO masers are rather closely related with the near-infrared `colors' and the equivalent black-body temperatures.Moreover,its upper limit is correlated with the 12μm and 25μm fluxes.This paper also briefly discusses the general function and specific role of SiO masers in the evolution of AGB stars.