Evolution of Circumgalactic Gas Flows

环银河系气流的演化

• 批准号: 1109288
• 负责人: Crystal Martin
• 金额: $ 45.55万
• 依托单位: University of California-Santa Barbara
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-15 至 2015-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1109288&HistoricalAwards=false
• 关键词: Evolution; Circumgalactic; Gas; Flows

This project, renewing a previous award, will continue work on the problem of how mass, energy, and elements heavier than helium ("metals") cycle in and out of galaxies over the interval when half the stellar mass now present in galaxies was forming. Under the prior award, the proposing team acquired spectra of several hundred galaxies in the relevant range of redshifts. They will use these data to extend the galaxy mass-metallicity relation to lower stellar masses, and will investigate the effect of shock excitation on metallicity diagnostics using both existing and new integral-field spectroscopic data. New observations will be obtained using new instrumentation becoming available at the Keck Observatory and on the Very Large Telescope, with an emphasis on detailed follow-up spectroscopy. The team will make use of fluorescent line emission to try to resolve discrepant galactic wind velocities obtained from absorption lines partially filled by emission, and will improve their modeling of line profiles, by adapting a theory developed for hot star winds and also by numerical ray tracing through a 3-dimensional hydrodynamic simulation. As a byproduct, the team will improve knowledge of the scaling relations between outflow properties and galaxy properties, and constrain the physical nature of the acceleration mechanism. The project provides support for the third year of a Postdoctoral Scholar appointment for a female scientist and funds the dissertation research of a graduate student; and the Principal Investigator will continue her program of community outreach activities. The team intends to make their line-fitting code and the data from their survey for ultra-faint, emission-line galaxies publically available.

这个项目，更新了以前的奖项，将继续研究质量，能量和比氦重的元素（“金属”）如何在星系中循环进出星系的问题，当时星系中一半的恒星质量正在形成。在先前的奖项下，提出建议的团队获得了数百个星系在相关红移范围内的光谱。他们将使用这些数据将星系质量-金属丰度关系扩展到较低的恒星质量，并将使用现有和新的积分场光谱数据研究冲击激发对金属丰度诊断的影响。将利用凯克天文台和甚大望远镜上现有的新仪器进行新的观测，重点是详细的后续光谱学。该小组将利用荧光线发射，试图解决从部分被发射填满的吸收线获得的不一致的银河风速度，并将通过采用为热星星风开发的理论以及通过三维流体动力学模拟进行数值射线追踪，改进其线轮廓建模。作为副产品，该团队将提高外流特性和星系特性之间的标度关系的知识，并限制加速机制的物理性质。该项目为一名女科学家的博士后学者任命提供第三年的支助，并为一名研究生的论文研究提供资金;首席研究员将继续其社区外联活动方案。该团队打算使他们的线拟合代码和他们对超微弱发射线星系的调查数据能够准确地获得。