Tracing the Evolution of Galaxies

AST 98-02978安德鲁·康诺利约翰霍普金斯大学追踪星系的演化 在过去的几年里，星系演化的研究已经成为观测天文学中最令人兴奋和最具活力的领域之一。 我们现在看到全球共动光度密度的快速上升（即，星星形成率）从零的红移到大约Z为1.5的峰值。 在更高的红移，星星的形成率似乎普遍下降。 这些都是定性描述。 康诺利博士正在量化特定星系群的演化。 他有一套统计技术，可以从宽带测光中估计星系的红移。 他希望能将观测到红移的星系数量从几千个增加到五万多个。 然后，他将跟踪光谱类型和形态的星系光度函数的演变。 在红移区间1 z 2中的星星形成活动是进化之谜中另一个缺失的部分。 康诺利博士正在用哈勃太空望远镜进行一项发射线调查，以确定巴耳末线、氢线以及OIII线。 这将获得第一个系统选择的星系样本在这个红移范围内。 ***

AST 98-02978 Andrew Connolly Johns Hopkins University Tracing the evolution of galaxies Over the last few years the study of the evolution of galaxies has emerged as one of the most exciting and dynamic areas of observational astronomy. We now see a rapid rise in the global comoving luminosity density (i.e., star formation rate) from a redshift of zero to a peak about z of 1.5. At higher redshifts there appears to be a general decline in the star formation rate. These are qualitative descriptions. Dr. Connolly is quantifying how particular galaxy populations evolve. He has a suite of statistical techniques for estimating the redshifts of galaxies from broadband photometry. He expects to increase the number of galaxies with observed redshift from a few thousand to more than fifty thousand. He will then trace the evolution of the galaxy luminosity function of spectral type and morphology. Star formation activity in the redshift interval 1 z 2 is another missing piece of the evolutionary puzzle. Dr. Connolly is undertaking an emission line survey with the Hubble Space Telescope to identify the Balmer line, H ( of hydrogen as well as OIII lines. This will derive the first systematically selected sample of galaxies in this redshift range. ***