Spectroscopic Investigations of Massive Binaries

AST-0205297 PI GiesThe大多数最大质量的恒星都是以紧密的配对方式诞生的，它们注定要在一生中相互作用。伴星的影响可以极大地改变恒星的演化路径：质量供体可以被剥离到原始大小的一小部分，而质量增益者可以成为更大质量和更明亮的恒星。这些被改变的恒星最终会爆炸成为奇特的超新星，它们的残余物主导着高能宇宙的外观（如包含中子星和黑洞的大质量X射线双星）。虽然双星演化的起点和终点已经被理解，但形成中间阶段的过程仍然是神秘的，质量和角动量转移和损失的问题仍然存在很大的不确定性。 这个项目将通过对一些关键系统的光谱研究，在进化的各个阶段调查这些过程。第一部分是对24个具有难以发现同伴的新双星的目标的调查。第二部分是在两个当前相互作用的系统中，在星周气体中形成的H α发射通量的轨道分析。第三部分探讨了快速旋转恒星的质量转移和自旋之间的联系，并包括寻找Be恒星的微弱质量转移后的同伴。最后一个部分是一个联合H α-X射线研究质量转移的大质量X射线双星记录在广泛的H α光谱获得的KPNO Coude饲料望远镜。

AST-0205297PI GiesThe majority of the most massive stars are born in close pairs that are destined to interact over their lifetime. The influence of a companion can dramatically alter the evolutionary paths of the stars: the mass donors can be stripped down to a fraction of their original size while the mass gainers can become rejuvenated as more massive and luminous stars. These altered stars will eventually explode as peculiar supernovae, and their remnants dominate the appearance of the high energy universe (as massive X-ray binaries containing neutron stars and black holes). Although the starting and end-points of binary evolution are understood the processes that forge the intermediate stages are still mysterious, and great uncertainties surround the issues of mass and angular momentum transfer and loss. This project will be an investigation of these processes at various stages in the evolutionary drama through spectroscopic studies of a number of key systems. The first part is a survey of two dozen targets for new binaries with hard to detect companions. The second section is an orbital analysis of the H a emission flux formed in the circumstellar gas in two currently interacting systems. The third part examines the link between mass transfer and the spin up of rapidly rotating stars, and includes a hunt for faint post-mass transfer companions of Be stars. The final component is a joint H a -X-ray study of mass transfer in massive X-ray binaries as documented in extensive H a spectroscopy obtained with the KPNO Coude Feed Telescope.***