具有不完全数据集的光学偏振光谱法
Optical spectropolarimetry with incomplete data sets
摘要：
线性分光偏振法是一种“光子饥饿”观测技术，需要特定的观测序列来确定斯托克斯Q和U参数。对于双光束分光偏振计，可以理想地使用在N = 2个延迟板位置处的观察来确定参数。由仪器效应引入的附加偏振信号需要N = 4个观测的冗余来校正这些效应。我们希望确定"仪器特征校正"，eQ和eU，对于双光束分光偏振仪的观测是否相同。例如，当在N = 3延迟板角度下获得观测时，我们希望确定是否可以使用一个斯托克斯参数的完整测量和相关的仪器特征校正来确定另一个斯托克斯参数。我们建立了一个通用的双光束分光偏振计的解析模型和蒙特卡罗模型，研究影响eQ = eU假设的因素。我们比较了这些模型与VLT FORS 1分光偏振。我们发现eQ-eU = 0，零附近的方差（Δ（eQ-eU））与观测值的信噪比直接相关。在2002 - 2007年期间，对一颗偏振标准星的观测表明，eQ-eU = 0的假设基本上是正确的，尽管eQ和eU的绝对值在不同的观测时期有所不同。不完整的分光偏振数据集可以在eQ = eU的假设下进行分析。使用双光束分光偏振仪的分光偏振分析的这种性质可以用于评估完整数据的还原质量。
英文摘要：
Linear spectropolarimetry is a ``photon-hungry'' observing technique, requiring a specific sequence of observations to determine the Stokes Q and U parameters. For dual-beam spectropolarimeters, the parameters can be ideally determined using observations at N=2 retarder plate positions. The additional polarization signal introduced by instrumental effects requires the redundancy of N=4 observations to correct for these effects. We wish to determine if the ``instrumental signature corrections'', eQ and eU, are identical for observations with dual-beam spectropolarimeters. For instances when observations were acquired at N=3 retarder plate angles, we wish to determine if the complete measurement of one Stokes parameter and the associated instrumental signature correction can be used to determine the other Stokes parameter. We constructed analytical and Monte Carlo models of a general dual-beam spectropolarimeter to study the factors affecting the assumption eQ=eU. We compared these models with VLT FORS1 spectropolarimetry. We find that eQ-eU=0, with the variance around zero (Δ(eQ-eU)) being directly related to the signal-to-noise ratio of the observations. Observations of a polarized standard star, over the period 2002-2007, show that the assumption of eQ-eU=0 is generally true, although the absolute values of eQ and eU vary between observational epochs. Incomplete spectropolarimetry datasets can be analyzed under the assumption that eQ=eU. This property of the analysis of spectropolarimetry, with dual beam spectropolarimeters, can be used to assess the quality of the reduction for complete data.
机构、总结、中文摘要均由AI分析而来，可能存在错误，请以论文正文为准。
