论文标题
GPS测量可降水蒸气可以改善调查校准：KPNO和Mayall Z频段遗产调查的演示
GPS Measurements of Precipitable Water Vapor Can Improve Survey Calibration: A Demonstration from KPNO and the Mayall z-band Legacy Survey
论文作者
论文摘要
我们在这里表明，KPNO处沉淀水蒸气（PWV）的双波段GPS测量可以预测Mayall Z频段遗产调查（MZLS）的总体人均敏感性。单个恒星亮度的每图像变化与测得的PWV和恒星的颜色密切相关。我们使用合成的恒星光谱和小吃传输模型来预测预期的PWV诱导的光度误差，并与观测值保持良好的一致性。我们还发现，通过与PWV_EFF的线性关系可以很好地透露PWV吸收，并介绍了文献中传统治疗方法的更新。 在合理观察条件的范围内，MZLS零点随着127 mmag的标准偏差而变化。随着时间的流逝，这种变化以灰色的世俗趋势为主，这与在〜114 mmag变化的光学表面上逐渐积累了污染。基于恒星光谱和详细的PWV吸收模型的PWV校正PWV，另外为零点变化的47 mmag。在PWV上，MZL每图像敏感性降低了约40 mmag。蓝色（R-Z <0.5 mag）和红色（1.2 mag <r-Z）恒星之间的差异增加了3.25 mmag，而PWV有效mm。 这些结果表明需要高精度光度测量同时监测PWV。我们发现，该GPS系统提供的PWV测量值比使用不同颜色的星星的差异测量值更精确，并建议观察者安装双波段GPS作为低维护，相对较低的成本，辅助校准系统。我们通过对三种感兴趣的科学案例的PWV光度影响进行计算，扩展了对PWV测量进行良好校准的PWV测量的结果：恒星光度法，超新星宇宙学以及类星体的识别和可变性。
We here show that dual-band GPS measurements of precipitable water vapor (PWV) at KPNO predict the overall per-image sensitivity of the Mayall z-band Legacy Survey (MzLS). The per-image variation in the brightness of individual stars is strongly correlated with the measured PWV and the color of the star. We use synthetic stellar spectra and TAPAS transmission models to predict the expected PWV-induced photometric errors and find good agreement with the observations. We also find that PWV absorption can be well-approximated by a linear relationship with PWV_eff and present an update on the traditional treatment in the literature. Within the range of reasonable observing conditions, the MzLS zero point varies with a standard deviation of 127 mmag. This variation is dominated by a gray secular trend with time, consistent with a gradual accumulation of contamination on optical surfaces that accounts for ~114 mmag of variation. Correcting for PWV based on a suite of stellar spectra and detailed PWV absorption models accounts for another 47 mmag of zero-point variation. The MzLS per-image sensitivity is decreased by ~40 mmag per effective mm of PWV. The difference between blue (r-z < 0.5 mag) and red (1.2 mag < r-z) stars increases by 3.25 mmag per effective mm of PWV. These results show the need for high-precision photometric surveys to simultaneously monitor PWV. We find that this GPS system provides more precise PWV measurements than using differential measurements of stars of different colors and recommend that observatories install dual-band GPS as a low-maintenance, relatively low cost, auxiliary calibration system. We extend our results of the need for well-calibrated PWV measurements by presenting calculations of the PWV photometric impact on three science cases of interest: stellar photometry, supernova cosmology, and quasar identification and variability.
