Microlensing Theory: Applications to Stellar and Galactic Astrophysics

AST 0201266GouldMicrolensing观测能力正在继续在几个方向上迅速扩展：微透镜首次被用于寻找行星和探测恒星大气层。对M31的微透镜调查正在返回他们的第一个候选事件的实质性列表。在接下来的十年里，微透镜应该会给我们一个详细的银河系隆起质量函数的图片，直到0.01太阳质量。这些发展带来了新的理论挑战和新的观测机会。与此同时，它们为微透镜和银河系结构研究之间的强大相互作用奠定了基础。俄亥俄州州立大学的安德鲁·古尔德博士将在这些发展的基础上开展两个具体的项目。 1.双星和行星简并的表征和解析。双星系统和行星系统的微透镜效应通常会引起光变曲线中的焦散性跳跃，这两者都表明双星或行星的存在，并且可以用来了解被透镜作用的源星星的大气。然而，为了完全提取该信息，需要对透镜系统的几何形状进行明确的重建。古尔德博士已经证明，即使在微透镜测光方面有了惊人的进步，二元光变曲线也可能受到多种解释的影响。他已经解决了将这些简并现象分类（从而理解如何打破）为更大的二元透镜事件子类的问题。现在，他将对较小但更困难（通常也更有价值）的子类进行类似的研究。同样，他已经解决了行星简并性的较大子类的分类问题，现在将处理较小的，更困难的子类。 2. M31的像素透镜。 古尔德博士将继续他正在进行的M31微透镜观测计划，并将继续将获得的数据提供给竞争小组。良好的时间覆盖仍然是这一领域最薄弱的环节，因此古尔德博士使用MDM 1.3米和2.4米望远镜至关重要。 几乎同样重要的科学成果获得，是研究生谁将做的工作的实质性部分的培训。古尔德博士开发了一种非常密集和互动的培训学生的模式，取得了非常成功的结果，并将继续获得这个奖项。

AST 0201266GouldMicrolensing observational capabilities are continuing to expand rapidly in several directions: for the first time, microlensing is being used to look for planets and probe the atmospheres of stars. Microlensing surveys toward M31 are returning their first substantial lists of candidate events. Within the next decade, microlensing should give us a detailed picture of the galactic bulge mass function down to 0.01 solar masses. These developments are presenting both new theoretical challenges and new observational opportunities. At the same time, they lay the basis for a strong interplay between microlensing and Galactic-structure studies. Dr. Andrew Gould, at Ohio State University, will build on these developments with two specific projects. 1. Characterization and Resolution of Binary and Planetary Degeneracies. Microlensing by binary and planetary systems often gives rise to dramatic caustic-induced jumps in the light curve, that both signal the presence of the binary or planet, and can be exploited to learn about the atmosphere of the source star being lensed. However, to fully extract this information, an unambiguous reconstruction of the geometry of the lensing system is required. Dr. Gould has demonstrated that even with the spectacular improvements in microlensing photometry, binary light curves can be subject to multiple interpretations. He has already solved the problem of classifying (and so understanding how to break) these degeneracies for the larger subclass of binary-lensing events. He will now do an analogous study of the smaller, but more difficult (and often more valuable) subclass. Similarly, he has already solved the problem of classifying the larger subclass of planetary degeneracies, and will now tackle the smaller, more difficult subclass. 2. Pixel Lensing of M31. Dr. Gould will continue his ongoing program of microlensing observations of M31, and will continue to give the data so acquired to competing groups. Good temporal coverage remains the weakest link in this subfield, so Dr. Gould's access to the MDM 1.3m and 2.4m telescopes can be of critical importance. Of almost equal importance to the scientific results to be obtained, is the training of the graduate students who will do a substantial part of the work. Dr. Gould has developed a very intensive and interactive mode of training students with extremely successful results, and that will continue with this award.***