The RoboPol sample of optical polarimetric standards
The RoboPol sample of optical polarimetric standards
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光学偏振标准品 RoboPol 样品
DOI：
10.1051/0004-6361/202346778
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发表时间：
2023
影响因子：
6.5
通讯作者：
Mandarakas, N.
中科院分区：
文献类型：
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作者：
Blinov, D.;Maharana, S.;Bouzelou, F.;Casadio, C.;Gjerløw, E.;Jormanainen, J.;Kiehlmann, S.;Kypriotakis, J. A.;Liodakis, I.;Mandarakas, N.
背景光学偏振计通常使用具有已知且稳定的偏振参数的恒星测量来校准。然而，天空中却缺乏这样的星星。目前可用的许多标准由于亮度较高而不适用于中型和大型望远镜。此外，正如我们发现的，一些使用的偏振标准实际上是可变的，或者具有与其编目值不同的偏振参数。目标我们的目标是建立一个稳定的标准样本，适合校准线性光学偏振计，精度低至 10−3in 分数偏振。方法 4 年以来，我们一直在对由分布在北方天空的 107 颗恒星组成的候选标准样本进行监测活动。我们分析了这些恒星线性偏振的变化性，同时考虑到分数偏振测量的非高斯性质。对于九颗恒星的子样本，我们还进行了多波段偏振测量。结果我们创建了一个包含 65 颗恒星的新目录（参见 ），这些恒星很稳定，测量的偏振参数不确定性很小，可以用作中型和大型望远镜的偏振计校准器。
ContextOptical polarimeters are typically calibrated using measurements of stars with known and stable polarization parameters. However, there is a lack of such stars available across the sky. Many of the currently available standards are not suitable for medium and large telescopes due to their high brightness. Moreover, as we find, some of the polarimetric standards used are in fact variable or have polarization parameters that differ from their cataloged values.AimsOur goal is to establish a sample of stable standards suitable for calibrating linear optical polarimeters with an accuracy down to 10−3in fractional polarization.MethodsFor 4 yr, we have been running a monitoring campaign of a sample of standard candidates comprised of 107 stars distributed across the northern sky. We analyzed the variability of the linear polarization of these stars, taking into account the non-Gaussian nature of fractional polarization measurements. For a subsample of nine stars, we also performed multiband polarization measurements.ResultsWe created a new catalog of 65 stars (see ) that are stable, have small uncertainties of measured polarimetric parameters, and can be used as calibrators of polarimeters at medium and large telescopes.