090275

Stacking of SZ signals (Y) by stellar mass produces a significant signal which has been used to infer the halo gas mass of galaxies. Interpreting the stacked signal assumes the Y distribution (at fixed M*) is narrow symmetric and for a uniform sample of objects. These conditions are violated when stacking in stellar mass bins so one must understand the distribution of Y as a function of galaxy environment (M* gal/M*tot). This cannot be obtained from the weak individual SZ signals but can be inferred from X-ray observations. We propose to complete our X-ray studies of 15 nearby galaxies that were previously used in a stack of SZ signals. We will measure the distribution of Y _X (X-ray analog of SZ) to quantify the dependence of halo gas mass on galaxy environment. [truncated! Please see actual data for full text]通过按恒星质量对苏尼亚耶夫-泽尔多维奇（Sunyaev-Zel'dovich，SZ）信号（记为Y）进行堆叠，可得到显著的观测信号，该信号曾被用于推断星系的晕气体质量。对堆叠信号的解读默认存在两个前提：其一，在固定恒星质量M*的条件下，Y的分布呈窄对称形态；其二，样本中的天体均一。但当按恒星质量区间进行堆叠时，上述前提往往无法满足，因此必须明确Y的分布随星系环境（即单个星系恒星质量与总恒星质量之比M* gal/M*tot）的变化关系。这一关系无法通过微弱的单个SZ信号获取，但可通过X射线观测进行推断。我们提议对此前用于SZ信号堆叠研究的15个邻近星系开展完整的X射线研究，通过测量Y_X（SZ信号的X射线类比量）的分布，量化晕气体质量随星系环境的依赖关系。[文本已截断！请查阅完整数据集原文以获取全部内容]