Calibrating Astronomical Instruments to Improve the Science Gained from the Large Synoptic Survey Telescope

美国未来的大型天文观测望远镜(LSST)将通过获取长时间重复观测的物体的图像来彻底改变天文学。这些观察将是极其准确的。为了从这些观测中获得最好的科学，还将使用两种额外的辅助观测：过去使用不同望远镜和仪器进行的观测，以及未来将使用其他望远镜和仪器进行的观测。要使所有这些支持观测有用，它们必须与将使用LSST进行的观测一样准确。在这个项目中，天文学家将对正在或将要进行其他观测的天文台的望远镜、仪器和天空条件进行校准。该项目服务于国家利益，因为它确保用新望远镜获得的数据将有助于尽可能获得最好的科学结果，促进观测天文学的进步。这些天文学家来自德克萨斯农工大学，该校的大部分学生都来自拉美裔人口。研究人员计划雇用两名研究生和8-10名本科生。大型天文观测望远镜(LSST)项目将产生大量的光度数据，这将给天文学领域带来革命性的变化。LSST的目标之一是提供前所未有的光度测量精度：0.5%。来自其他望远镜的现有和正在进行的数据将用于与新的LSST观测进行比较和后续观测。然而，这些观察结果需要非常好地校准。研究人员将使用现有设备为世界各地天文台的成像系统提供准确的分光光度校准。校准将包括对望远镜、光学元件、滤光片和探测器的现场测量，提供仪器传输剖面的详细知识。还将测量天文台站点上方的大气传输。总而言之，这些测量将有助于对这些系统进行异常精确的光度校准。根据对DECAM仪器和Cerro Tololo美洲天文台位置的类似测量，调查人员估计，拟议的工作应能在大型调查和所有光谱波段上实现约0.2%的精度。

The future Large Synoptic Survey Telescope (LSST) of the United States will revolutionize astronomy by obtaining images of objects observed repeatedly over long periods of time. These observations will be extremely accurate. In order to get the best science from these observations, two types of additional, supporting observations will also be used: observations that have been made using different telescopes and instruments in the past, and observations that will be made with other telescopes and instruments in the future. For all of these supporting observations to be useful, they must be as accurate as the observations that will be taken using the LSST. For this project, the astronomers will calibrate the telescopes, instruments, and sky conditions of the observatories where the other observations are or will be made. This project serves the national interest, as it ensures that the data acquired with the new telescope will contribute the best scientific results possible, promoting the progress of observational astronomy. The astronomers are from Texas A & M University, which draws most of its students from a heavily Hispanic population. The investigators intend to employ two graduate students and 8 - 10 undergraduate students.The Large Synoptic Survey Telescope (LSST) project will produce an enormous amount of photometric data that will revolutionize the field of astronomy. One of the LSST goals is to provide an unprecedented level of photometric accuracy: 0.5%. Existing and on-going data from other telescopes will be used for comparison and follow-up observations with the new LSST observations. These observations, however, will need to be very well calibrated. The investigators will use existing equipment to provide accurate spectrophotometric calibration of imaging systems at observatories around the world. The calibration will include in-situ measurements of the telescopes, optics, filters, and detectors, providing detailed knowledge of the transmission profiles of the instruments. The atmospheric transmission above the observatory sites will also be measured. Together, these measurements will help to enable exceptionally accurate photometric calibration of these systems. Based on similar measurements of the DECam instrument and the Cerro Tololo Inter-American Observatory location, the investigators estimate that the proposed work should allow for accuracy of ~0.2% across large surveys and all spectral bands.