An Improved Accounting: Searching for Faint Dwarf Galaxies Beyond the Local Group

暗矮星系是大型星系的组成部分，被假设为宇宙中最丰富的星系。 由于它们的质量较低（因此，引力结合能较低），它们最容易受到任何移除或阻止气体凝结形成恒星的过程的影响。然而，因为它们是如此暗淡，唯一被充分研究的暗矮星样本是由包括我们银河系在内的本星系群中的暗矮星组成的。 该项目希望利用深度成像数据来回答一些关于暗矮星系的开放性问题：它们在本地宇宙中有多丰富？ 它们的恒星质量和它们的看不见的“暗物质”晕之间的关系是什么？ 在暗淡的矮星系中，什么过程终止了星星的形成？ 研究人员还将利用矮星系搜索作为增加学生进入STEM职业的一种方式。他们将为参加俄亥俄州超级计算机中心一年一度为期两周的暑期研究所的天才高中生开发一个矮星系狩猎项目，并增加参与该项目的机会，包括通过该项目资助的奖学金。该团队将制作一个“这就是我们如何科学”的视频博客（vlog）。 这篇视频日志将跟随研究人员完成与该项目相关的里程碑和日常任务，还将为对科学事业感兴趣的年轻学生提供操作指南。该项目将利用Co-PI领导的“失败超新星”调查中现有的深多波长大型双目望远镜成像数据，对附近宇宙中的微弱矮星系进行普查。 这21个宿主星系涵盖了预计将容纳本宇宙中大多数微弱矮星的星系类型。 分析，半分析和数值工具将被用来推断暗矮星的恒星质量和它们的暗物质晕之间的关系，并推断暗矮星在当地宇宙中的数密度。这些模型也将被用来调查相对强度的环境，内部和全球淬火的星星形成，作为主机类型和微弱的矮恒星质量的函数。

Faint dwarf galaxies are the building blocks of large galaxies, and are hypothesized to be the most abundant galaxies in the Universe. Because of their low mass (thus, low gravitational binding energies), they are the most susceptible to any process that removes or prevents gas from condensing to form stars. However, because they are so dim, the only well-studied sample of faint dwarfs consists of those in the Local Group of Galaxies that includes our own Milky Way galaxy. This project expects to answer some of the open questions about faint dwarf galaxies using deep imaging data: How abundant are they in the local Universe? What is the relation between the mass of their stars and their halos of invisible "dark matter"? Which processes terminate star formation in faint dwarf galaxies? The researchers will also leverage dwarf galaxy searches as a way to increase student access to STEM careers. They will develop a dwarf-galaxy-hunting project for gifted high-school students attending the Ohio Supercomputer Center's annual two-week Summer Institute, and increase access to the program including through scholarships to be funded via this project. The team will produce a "This Is How We Science" video blog (vlog). This vlog will follow the researchers through the milestones and daily tasks associated with the project, and will also feature a how-to guide for young students interested in scientific careers.The project will take a census of faint dwarf galaxies in the nearby Universe using existing deep, multi-wavelength Large Binocular Telescope imaging data from a "failed supernova" survey led by the Co-PI. The 21 host galaxies span the range of galaxy types expected to host most of the faint dwarfs in the local Universe. Analytic, semi-analytic, and numerical tools will be used to infer the relationship between the stellar masses of the faint dwarfs and their dark-matter halos, and to infer the faint dwarf number density in the local Universe. These models will also be used to investigate the relative strength of environmental, internal, and global quenching of star formation, as a function of host type and faint dwarf stellar mass.