• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文期刊>PASJ: Publications of the Astronomical Society of Japan >The stellar halo of the Milky Way traced by blue horizontal-branch stars in the Subaru Hyper Suprime-Cam Survey
【24h】

The stellar halo of the Milky Way traced by blue horizontal-branch stars in the Subaru Hyper Suprime-Cam Survey

机译：在斯巴鲁超级Suprime-CAM调查中追踪的银河系追踪的银河系的恒星光环

获取原文
获取原文并翻译 | 示例
           
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

We report on the global structure of the Milky Way (MW) stellar halo up to its outer boundary based on the analysis of blue horizontal-branch stars (BHBs). These halo tracers are extracted from the (g, r, i, z)-band multi-photometry in the internal data release of the ongoing Hyper Suprime-Cam Subaru Strategic Program (HSC-SSP) surveyed over a similar to 550deg(2) area. In order to select the most likely BHBs by removing blue straggler stars (BSs) and other contamination in a statistically significant manner, we have developed and applied an extensive Bayesian method, instead of the simple color cuts adopted in our previous work, where each of the template BHBs and non-BHBs obtained from the available catalogs are represented as a mixture of multiple Gaussian distributions in the color-color diagrams. We found from the candidate BHBs in the range of 18.5 < g < 23.5mag that the radial density distribution over a Galactocentric radius of r = 36-360kpc can be approximated as a single power-law profile with an index of or a broken power-law profile with an index of at r below a broken radius of kpc and a very steep slope of at r > r(b). The latter profile with a prolate shape having an axial ratio of is most likely and this halo may hold a rather sharp boundary at r similar or equal to 160kpc. The slopes of the halo density profiles are compared with those from the suite of hydrodynamical simulations for the formation of stellar halos. This comparison suggests that the MW stellar halo may consist of the two overlapping components: the in situ inner halo as probed by RR Lyrae stars showing a relatively steep radial density profile and the ex situ outer halo with a shallow profile probed by BHBs here, which is made by accretion of small stellar systems.
机译：基于蓝色水平分支恒星（BHBS）的分析，向其外边界达到其外边界的银河系（MW）Stellar Halo的全球结构。这些光晕示踪剂是从类似于550deg（2）的持续的超级Suprime-CAM Subaru战略计划（HSC-SSP）的内部数据释放中的（G，R，I，Z） - 带多光度测量器中提取的区域。为了通过以统计显着的方式删除蓝色孤立恒星（BSS）和其他污染，选择和应用广泛的贝叶斯方法，而不是我们以前的工作中采用的简单颜色切割，而且从可用目录中获得的模板BHB和非BHB被表示为颜色图中的多个高斯分布的混合。我们发现从候选BHB的范围内的18.5 r（b）的非常陡峭的斜率。具有轴向比的后一种具有轴向比的后一种轮廓最有可能并且该卤素可以在相似或等于160kpc的R处保持相当尖的边界。将光晕密度剖面的斜率与来自流体动力学模拟套件的斜率进行比较，以形成恒星晕。这种比较表明，MW恒星光环可以包括两个重叠部件：由RR Lyrae恒星探测的原位内光，显示出相对陡峭的径向密度曲线，并且在这里通过BHBS探测的浅轮廓的浅轮廓的浅层外光。由小型恒星系统的吸积。

著录项

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号