Probing the Nature and Origin of Ultra Diffuse Galaxies (UDGs) with Deep and Wide-Field Imaging

利用深视场和广视场成像探测超漫射星系 (UDG) 的性质和起源

• 批准号: 1812847
• 负责人: Jin Koda
• 金额: $ 48.7万
• 依托单位: SUNY at Stony Brook
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-06-15 至 2023-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1812847&HistoricalAwards=false
• 关键词: Probing; Nature; Origin; Ultra; Diffuse

Ultra-diffuse galaxies (UDGs) are a newly discovered population of galaxies. They are extremely faint, but spatially very extended, and are almost blended in the brightness of the night sky. Such diffuse galaxies are fragile, and cannot survive in gravitational encounters with other galaxies. However, astronomers are finding a great number of UDGs in clusters of galaxies, where such encounters would occur. This research program will investigate the nature and origin of these UDGs. It will study (1) whether UDGs are distinct from other types of galaxies such as the Milky Way and dwarf galaxies; (2) how they are protected from the gravitational disruptions; and (3) whether they have even fainter outskirts. The effects of gravitational encounters should appear clearly in the outskirts. This project will engage a variety of students in the research.This program will use deep and wide-field imaging of eight local clusters of galaxies. The data are taken with the Hyper Suprime-Cam (HSC) on the Subaru telescope. These unique data will show the very faint outskirts of UDGs, as well as their large-scale environments. The program will perform the most reliable census and resolved analysis of the UDG population within, outside, and among the clusters. The main goals are (1) to confirm whether UDGs are distinct from dwarf and normal galaxies in their properties parameter spaces; (2) to constrain how they formed and how they their properties depend on their environments; and (3) to image their fainter outskirts and to discover even fainter, more extended UDGs. The project focuses primarily on UDGs, but aims to yield a broader, coherent picture that connects UDGs, dwarfs, and normal galaxies. UDGs are faint and extended, and are difficult to be detected and analyzed. The observations and data reduction will be optimized to achieve these goals.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

超湿星系（UDGS）是新发现的星系群。它们非常微弱，但在空间上非常延伸，几乎被夜空的亮度混合在一起。这种弥漫性星系是脆弱的，无法在与其他星系的重力相遇中生存。但是，天文学家在星系群中发现了大量的UDG，在这些星系群中会发生这种相遇。该研究计划将研究这些UDG的性质和起源。它将研究（1）UDG是否与银河系和矮星系等其他类型的星系不同； （2）如何保护它们免受重力破坏； （3）他们是否甚至有郊区。引力相遇的影响应清楚地出现在郊区。该项目将吸引各种学生参与研究。该计划将使用八个本地星系群的深层和宽场成像。数据是在Subaru望远镜上使用超级胶卷（HSC）进行的。这些独特的数据将显示UDG的郊区及其大​​规模环境。该计划将对群集内部，外部和中间的UDG人群进行最可靠的人口普查和解决分析。主要目标是（1）确认在其性质参数空间中的UDG是否与矮人和正常星系不同； （2）限制它们的形成方式以及它们的性质如何取决于其环境； （3）为他们的郊区昏迷，发现甚至更宽敞的UDGS。该项目主要关注UDG，但旨在产生连接UDG，矮人和正常星系的更广泛，连贯的图片。 UDG是微弱和扩展的，很难被检测和分析。将对这些目标进行优化的观察结果和减少数据。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识分子优点和更广泛的影响评估标准来评估值得支持的。