Collaborative Project: A Comprehensive Survey of Hot Stars in the Galactic Bulge

Peterson，Ruth Astrophysical AdvancesAST-9900582博士。天体物理进展的彼得森和俄亥俄州州立大学的Terndrup将开展一项合作项目，调查银河系膨胀的热恒星，那些温度超过20，000 K的恒星，被认为是在古老的，富含金属的河外星系中发现的过量紫外线的来源。这些恒星是一个谜，因为在我们银河系中的球状星团的富金属系统中没有发现这样的恒星，但在椭圆星系和其他螺旋星系的凸起中显然很常见。这项光度和光谱测量将对我们银河系凸出部分的几个区域进行全面普查，初步工作已经发现了这些热恒星的统计学显著样本，并且可以获得足够大的富含金属的样本，以识别恒星演化的短寿命阶段的恒星。该调查将确定每个相关演化阶段的恒星数量，并在距离银河系中心不同距离的几个领域中推导出足够冷而不受扩散影响的恒星的金属丰度。

Peterson, RuthAstrophysical AdvancesAST-9900582Drs. Peterson, of Astrophysical Advances, and Terndrup, at the Ohio State University, will carry out a collaborative project to survey the Galactic bulge for hot stars, those with temperatures in excess of 20,000 K, that are thought to be the source of the excess Ultraviolet light found in old, metal-rich extragalactic systems. These stars have presented a puzzle, since such stars are not found in the metal-rich systems of globular clusters in our galaxy, yet are apparently common in elliptical galaxies and the bulges of other spiral galaxies. This photometric and spectroscopic survey will take a complete census of several fields in the bulge of our galaxy, where preliminary work has uncovered a statistically significant sample of these hot stars, and where large enough samples of a metal-rich population can be obtained to identify stars in short-lived phases of stellar evolution. The survey will identify the numbers of stars in each relevant evolutionary phase and derive metallicities for stars cool enough to be unaffected by diffusion, in several fields at varying distances from the Galactic center.