Seismological Investigations of Compact Objects

对于由普通气体组成的恒星，恒星地震学提供了一个机会，可以利用共振力学特性来获得有关恒星内部结构和成分的天文学有趣信息。对于白色矮星来说，地震学提供了类似的机会，也提供了学习基础物理学的机会。例如，人们怀疑白色矮星的电子简并核心在冷却过程中结晶，但建议结晶的计算需要观察证实。在这个项目中，克莱门斯博士将识别鲸鱼座ZZ恒星（脉动白色矮星）中的非径向脉动模式。地震学分析的第一步将通过两种新方法完成。对于较亮的目标（V 15.5），将使用南方天文台天体物理研究（SOAR）望远镜上的古德曼摄谱仪获得时间分辨光谱。线轮廓变化将被用来测量它们的球形度，即使在较低的信噪比。对于较暗的恒星，将使用Goodman摄谱仪或SOAR光学成像仪上的时间序列测光来测量组合模式的振幅，这可以用来识别它们的球形度。预计斯隆数字巡天计划发现的10-20颗最有趣的鲸鱼座ZZ星的模式将在这三年的努力中得到确定。这一项目将帮助支持北卡罗来纳州大学查佩尔山古德曼实验室从事最先进天文研究的研究生和本科生的多样化群体。古德曼实验室专门为学生提供天文仪器方面的经验，下一代仪器制造商的培训是社区的优先事项。

For stars made of ordinary gas, stellar seismology offers the opportunity to use resonant mechanical properties to derive astronomically interesting information about stellar interior structure and composition. For white dwarfs seismology offers similar opportunities as well as the chance to learn fundamental physics. For example, it is suspected that the electron degenerate cores of white dwarfs crystallize during cooling, but the calculations that suggest crystallization require observational confirmation. In this project, Dr. Clemens will identify non-radial pulsation modes in ZZ Ceti stars (pulsating white dwarfs). This first step in their seismological analysis will be accomplished through two new methods. For the brighter targets (V 15.5), time-resolved spectroscopy will be obtained with the Goodman spectrograph on the Southern Observatory for Astrophysical Research (SOAR) Telescope. Line profile variations will be used to measure their spherical degree, even at lower signal-to-noise ratios. For the fainter stars, time series photometry on the Goodman Spectrograph or the SOAR Optical Imager will be used to measure the amplitudes of combination modes, which can be used to identify their spherical degree. It is expected that the modes of 10-20 of the most interesting new ZZ Ceti stars discovered by the Sloan Digital Sky Survey will be identified during the three years of this effort.This project will help support a diverse group of graduate and undergraduate students engaged in state-of-the-art astronomical research in University of North Carolina at Chapel Hill's Goodman Laboratory. The Goodman Laboratory specializes in giving students experience in astronomical instrumentation and the training of the next generation of instrument builders is a priority of the community.