Large-scale retrospective relative spectrophotometric self-calibration in space
Large-scale retrospective relative spectrophotometric self-calibration in space
复制标题
空间大规模回顾性相对分光光度自校准
DOI：
10.1093/mnras/stx283
复制
发表时间：
2017
影响因子：
4.8
通讯作者：
Markovic K
中科院分区：
文献类型：
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作者：
Markovic K
我们考虑将重叠区域的相对自定标应用到使用无缝隙光谱的光谱星系调查中。这种方法是基于Padmanabhan等人为斯隆数字天空调查开发的方法。在这一点上，我们考虑对校准器亮度进行联合拟合和边际化，而不是将它们视为自由参数。然而，我们将探测器到探测器的校准与全焦平面曝光到曝光的校准分开。为了演示校准程序将如何工作，我们模拟了广泛欧几里得调查的光谱部分的潜在实现的程序。我们研究了不同抖动配置下流量测量中覆盖范围的变化和相对乘性误差的确定。我们使用新的方法来研究这样一种情况，即每一次曝光或探测器的平场被精确测量，并且仅存在曝光与曝光或探测器与探测器之间的通量误差变化。我们考虑了几种基本抖动模式，发现它们强烈地影响了使用这种方法进行校准的能力。为了实现自校准，重要的是测量策略将不同的观测连接在至少有最小重叠量的情况下，我们提出了满足这一要求的抖动的‘S’模式。欧几里德采用的最终调查战略将不得不针对一些不同的科学目标和要求进行优化。光谱星系探测的大范围校准显然在宇宙学上至关重要，但不是唯一的。我们将我们的模拟代码公布在githorb.com/diDamarkovic/ubercal上。
We consider the application of relative self-calibration using overlap regions to spectroscopic galaxy surveys that use slitless spectroscopy. This method is based on that developed for the Sloan Digital Sky Survey by Padmanabhan et al. in that we consider jointly fitting and marginalizing over calibrator brightness, rather than treating these as free parameters. However, we separate the calibration of the detector to detector from the full-focal-plane exposure-to-exposure calibration. To demonstrate how the calibration procedure will work, we simulate the procedure for a potential implementation of the spectroscopic component of the wideEuclidsurvey. We study the change of coverage and the determination of relative multiplicative errors in flux measurements for different dithering configurations. We use the new method to study the case where the flat-field across each exposure or detector is measured precisely and only exposure-to-exposure or detector-to-detector variation in the flux error remains. We consider several base dither patterns and find that they strongly influence the ability to calibrate, using this methodology. To enable self-calibration, it is important that the survey strategy connects different observations with at least a minimum amount of overlap, and we propose an ‘S’-pattern for dithering that fulfils this requirement. The final survey strategy adopted byEuclidwill have to optimize for a number of different science goals and requirements. The large-scale calibration of the spectroscopic galaxy survey is clearly cosmologically crucial, but is not the only one. We make our simulation code public on github.com/didamarkovic/ubercal.